GOODWILL AND INTANGIBLE ASSETS, NET

The following table presents goodwill by reportable segment:


(in thousands)	Index		Analytics		ESG and Climate		All Other - Private Assets		Total
Goodwill at December 31, 2022	$	1,201,622	$	290,976	$	48,047	$	689,025	$	2,229,670
Foreign exchange translation adjustment	1,726		—		—		1,063		2,789
Goodwill at June 30, 2023	$	1,203,348	$	290,976	$	48,047	$	690,088	$	2,232,459

Intangible Assets, Net

The following table presents the amount of amortization expense related to intangible assets by category for the periods indicated:


	Three Months Ended June 30,				Six Months Ended June 30,
(in thousands)	2023		2022		2023		2022
Amortization expense of acquired intangible assets	$	15,851	$	15,854	$	31,682	$	31,752
Amortization expense of internally developed capitalized software	10,303		6,325		19,139		12,147
Total amortization of intangible assets expense	$	26,154	$	22,179	$	50,821	$	43,899

The gross carrying and accumulated amortization amounts related to the Company’s intangible assets were as follows:


	As of
	June 30,		December 31,
(in thousands)	2023		2022
Gross intangible assets:
Customer relationships	$	532,500	$	532,500
Proprietary data	220,778		220,778
Acquired technology and software	209,220		209,220
Trademarks	208,190		208,190
Internally developed capitalized software	202,836		165,928
Subtotal	1,373,524		1,336,616

Foreign exchange translation adjustment	(9,864)		(13,214)
Total gross intangible assets	$	1,363,660	$	1,323,402

Accumulated amortization:
Customer relationships	$	(323,722)	$	(308,437)
Proprietary data	(51,334)		(41,783)
Acquired technology and software	(181,891)		(179,833)
Trademarks	(166,832)		(162,044)
Internally developed capitalized software	(95,913)		(77,259)
Subtotal	(819,692)		(769,356)

Foreign exchange translation adjustment	2,457		4,471
Total accumulated amortization	$	(817,235)	$	(764,885)

Net intangible assets:
Customer relationships	$	208,778	$	224,063

Proprietary data	169,444		178,995

Acquired technology and software	27,329		29,387

Trademarks	41,358		46,146

Internally developed capitalized software	106,923		88,670

Subtotal	553,832		567,260

Foreign exchange translation adjustment	(7,407)		(8,743)
Total net intangible assets	$	546,425	$	558,517

The following table presents the estimated amortization expense for the remainder of the year ending December 31, 2023 and succeeding years:


Years Ending December 31, (in thousands)	Amortization Expense
Remainder of 2023	$	54,950
2024	104,375
2025	79,120
2026	44,725
2027	36,644
Thereafter	226,611
Total	$	546,425