The carrying amount and accumulated amortization of the Company's software assets subject to amortization at each balance sheet date are as follows (in thousands):


	June 30, 2024						December 31, 2023
	Gross Carrying Amount		Accumulated Amortization		Net Balance		Gross Carrying Amount		Accumulated Amortization		Net Balance
Software for internal use	$	479,657	$	(379,457)	$	100,200	$	469,325	$	(360,907)	$	108,418

Amortization of software for internal use is computed using the straight-line method over an estimated useful life of generally three to eight years. Software for internal use amortization expense recorded during the three months ended June 30, 2024 and 2023, totaled $15.8 million and $16.0 million, respectively. Software for internal use amortization expense recorded during the six months ended June 30, 2024 and 2023, totaled $31.3 million and $33.0 million, respectively. These software amortization expense amounts are reflected in depreciation and amortization in the condensed consolidated statements of operations.

The carrying amount and accumulated amortization of the Company’s other intangible assets subject to amortization at each balance sheet date are as follows (in thousands):


	June 30, 2024						December 31, 2023
	Gross Carrying Amount		Accumulated Amortization		Net Balance		Gross Carrying Amount		Accumulated Amortization		Net Balance
Customer relationships	$	446,262	$	(267,661)	$	178,601	$	447,654	$	(252,828)	$	194,826
Trademarks and trade names	21,795		(21,795)		—		21,899		(21,079)		820
Total other intangible assets	$	468,057	$	(289,456)	$	178,601	$	469,553	$	(273,907)	$	195,646

Other intangible assets amortization expense recorded during the three months ended June 30, 2024 and 2023, totaled $8.2 million and $8.5 million, respectively. Other intangible assets amortization expense recorded during the six months ended June 30, 2024 and 2023, totaled $16.7 million and $16.9 million, respectively.

Based on capitalized intangible assets as of June 30, 2024, estimated amortization expense amounts in future fiscal years are as follows (in thousands):


Fiscal Year Ending December 31,	Software Amortization		Other Intangible Assets Amortization
Remainder of 2024	$	29,342	$	12,785
2025	42,369		20,977
2026	21,689		20,977
2027	5,281		20,713
2028	1,517		18,315
Thereafter	2		84,834
Total	$	100,200	$	178,601