Acquisitions, Goodwill and Intangible Assets VictorOps On June 22, 2018, we acquired 100% of the voting equity interest of VictorOps, Inc. (VictorOps), a privately-held Delaware corporation that develops incident management solutions for the IT and DevOps markets. This acquisition has been accounted for as a business combination. The purchase price of $112.3 million , paid in cash of $108.8 million and $3.5 million in fair value of replacement equity awards attributable to pre-acquisition service, was allocated as follows: $21.1 million to identified intangible assets, $1.7 million to net assets acquired, with the excess $89.5 million of the purchase price over the fair value of net tangible and intangible assets acquired recorded as goodwill, allocated to our one operating segment. Goodwill is primarily attributable to the value expected from the synergies of the combination, including combined selling opportunities with our products. This goodwill is not deductible for income tax purposes. The results of operations of VictorOps, which are not material, have been included in our condensed consolidated financial statements from the date of purchase. Additionally, we recognized $2.7 million of acquisition-related costs as general and administrative expense on our condensed consolidated statements of operations. Per the terms of the merger agreement with VictorOps, certain unvested stock options held by VictorOps employees were canceled and exchanged for replacement stock options to purchase shares of our common stock under our 2012 Equity Incentive Plan. Additionally, certain shares of stock issued under share-based compensation awards held by key employees of VictorOps were canceled and exchanged for unregistered restricted shares of our common stock subject to vesting. The portion of the fair value of the replacement equity awards associated with pre-acquisition service of VictorOps employees represented a component of the total purchase consideration, as discussed above. The remaining fair value of $7.6 million of these issued awards, which are subject to the recipients continued service with us and was excluded from the purchase price, will be recognized ratably as stock-based compensation expense over the required service period. The following table sets forth the components of identifiable intangible assets acquired and their estimated useful lives as of the date of acquisition: (In thousands, except useful life) Fair Value Useful Life (months) Developed technology $ 11,700 84 Customer relationships 9,400 60 Total intangible assets acquired $ 21,100 Phantom On April 6, 2018, we acquired 100% of the voting equity interest of Phantom Cyber Corporation (Phantom), a privately-held Delaware corporation that develops solutions for security orchestration, automation and response. This acquisition has been accounted for as a business combination. The purchase price of $303.8 million , paid in cash of $291.5 million and $12.3 million in fair value of replacement equity awards attributable to pre-acquisition service, was allocated as follows: $44.1 million to identified intangible assets, $10.5 million to net assets acquired, $3.3 million to net deferred tax liability, with the excess $252.5 million of the purchase price over the fair value of net tangible and intangible assets acquired recorded as goodwill, allocated to our one operating segment. Goodwill is primarily attributable to the value expected from the synergies of the combination, including combined selling opportunities with our products. This goodwill is not deductible for income tax purposes. The results of operations of Phantom, which are not material, have been included in our condensed consolidated financial statements from the date of purchase. Additionally, we recognized $3.3 million of acquisition-related costs as general and administrative expense on our condensed consolidated statements of operations. Per the terms of the merger agreement with Phantom, certain shares of stock issued under share-based compensation awards held by key employees of Phantom were canceled and exchanged for replacement equity awards consisting of unregistered restricted shares of our common stock subject to vesting. The portion of the fair value of the replacement equity awards associated with pre-acquisition service of Phantoms key employees represented a component of the total purchase consideration, as discussed above. The remaining fair value of $62.2 million of these issued awards, which are subject to the recipients continued service with us and thus excluded from the purchase price, will be recognized ratably as stock-based compensation expense over the required service period. The following table sets forth the components of identifiable intangible assets acquired and their estimated useful lives as of the date of acquisition: (In thousands, except useful life) Fair Value Useful Life (months) Developed technology $ 34,400 84 Customer relationships 9,700 60 Total intangible assets acquired $ 44,100 Goodwill There were no impairments to goodwill during the six months ended July 31, 2019 or during prior periods. Intangible Assets Intangible assets subject to amortization realized from acquisitions as of July 31, 2019 are as follows: (In thousands, except useful life) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted-Average Remaining Useful Life (months) Developed technology $ 132,100 $ (69,394 ) $ 62,706 49 Customer relationships 20,910 (6,433 ) 14,477 46 Other acquired intangible assets 3,270 (3,036 ) 234 4 Total intangible assets subject to amortization $ 156,280 $ (78,863 ) $ 77,417 Intangible assets subject to amortization realized from acquisitions as of January 31, 2019 are as follows: (In thousands, except useful life) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted-Average Remaining Useful Life (months) Developed technology $ 132,100 $ (57,596 ) $ 74,504 52 Customer relationships 20,910 (4,523 ) 16,387 52 Other acquired intangible assets 3,270 (2,539 ) 731 9 Total intangible assets subject to amortization $ 156,280 $ (64,658 ) $ 91,622 Amortization expense from acquired intangible assets was $7.1 million and $6.3 million for the three months ended July 31, 2019 and 2018 , respectively, and $14.2 million and $11.0 million for the six months ended July 31, 2019 and 2018 , respectively. The expected future amortization expense for acquired intangible assets as of July 31, 2019 is as follows: Fiscal Period (In thousands) Expected Amortization Expense Remaining fiscal 2020 $ 13,737 Fiscal 2021 23,780 Fiscal 2022 13,701 Fiscal 2023 10,406 Fiscal 2024 7,692 Thereafter 8,101 Total amortization expense $ 77,417