| Goodwill and Intangible Assets, Net |
Goodwill and Intangible Assets, Net Activity in goodwill was as follows: | | | | | | | (in thousands) | | Balance at December 31, 2025 | $ | 397,098 | | | Additions | 243,693 | | | | | Balance at March 31, 2026 | $ | 640,791 | |
Below is a summary of intangible assets, net: | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Definite-Lived | | Indefinite-Lived | | Total | | (in thousands) | Gross Book Value | | Accumulated Amortization | | Net Book Value | | Net Book Value | | Net Book Value | | Balances at December 31, 2025 | $ | 810,021 | | | $ | (524,910) | | | $ | 285,111 | | | $ | 42,298 | | | $ | 327,409 | | | Additions | 307,000 | | | — | | | 307,000 | | | — | | | 307,000 | | | Intangible amortization | — | | | (15,175) | | | (15,175) | | | — | | | (15,175) | | | Balances at March 31, 2026 | $ | 1,117,021 | | | $ | (540,085) | | | $ | 576,936 | | | $ | 42,298 | | | $ | 619,234 | |
Definite-lived intangible asset amortization for the remainder of fiscal year 2026 and succeeding fiscal years is estimated as follows: | | | | | | | | | | Fiscal Year | | Amount
(in thousands) | | Remainder of 2026 | | $ | 60,140 | | | 2027 | | 76,262 | | | 2028 | | 70,432 | | | 2029 | | 64,835 | | | 2030 | | 63,410 | | | 2031 and thereafter | | 241,857 | | | Total | | $ | 576,936 | |
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