GOODWILL AND OTHER INTANGIBLE ASSETS

6 Months Ended

Jun. 30, 2021

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Other Intangible Assets

GOODWILL AND OTHER INTANGIBLE ASSETS

There was no change in the carrying amount of goodwill for the three or six months ended June 30, 2021.

Changes in the carrying amount of goodwill consists of the following activity for the three and six months ended June 30, 2020 (in thousands):

Balance at December 31, 2019	$	1,425,542
Merger purchase accounting adjustments	2,341
Balance at March 31, 2020	$	1,427,883
Merger purchase accounting adjustments	727
Balance at June 30, 2020	$	1,428,610

The carrying amount and accumulated amortization of intangible assets consists of the following as of June 30, 2021 and December 31, 2020 (in thousands):

	June 30, 2021		December 31, 2020
Gross intangible assets:
Referral sources	$	456,372	$	438,121
Trademarks/names	44,536		44,536
Other amortizable intangible assets	402		402
Total gross intangible assets	501,310		483,059
Accumulated amortization:
Referral sources	(123,903)		(110,498)
Trademarks/names	(25,347)		(21,146)
Other amortizable intangible assets	(385)		(363)
Total accumulated amortization	(149,635)		(132,007)
Total intangible assets, net	$	351,675	$	351,052

Amortization expense for intangible assets was $9.0 million and $17.6 million for the three and six months ended June 30, 2021, respectively. Amortization expense for intangible assets was $8.8 million and $17.6 million for the three and six months ended June 30, 2020, respectively.