| Intangibles |
(4) Intangibles All customer relationships are subject to amortization and are amortized over a weighted average period of 21 years, which reflects the remaining economic life of the relationships as of June 30, 2026. The carrying amount of customer relationships were as follows: | | | | | | | | | | | | | (Unaudited) | | | | December 31, | | June 30, | | (in thousands) | | 2025 | | 2026 | | Gross carrying value of customer relationships | | $ | 1,555,000 | | | 2,177,148 | | Accumulated amortization of customer relationships | | | (480,913) | | | (524,925) | | Customer relationships | | $ | 1,074,087 | | | 1,652,223 | |
Future amortization expense as of June 30, 2026 is as follows (in thousands): | | | | | | | | Remainder of year ending December 31, 2026 | | | | | $ | 45,747 | | Year ending December 31, 2027 | | | | | | 91,495 | | Year ending December 31, 2028 | | | | | | 91,495 | | Year ending December 31, 2029 | | | | | | 91,495 | | Year ending December 31, 2030 | | | | | | 91,495 | | Thereafter | | | | | | 1,240,496 | | Total | | | | | $ | 1,652,223 | |
|