Goodwill and Other Intangible Assets - Rollforward of Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020
Finite-lived Intangible Assets [Roll Forward]
CDI and CRI Balance, beginning of period	$ 109,646		$ 117,573
CDI and CRI Balance, end of period	100,550	$ 109,646	117,573
Finite-lived Intangible Assets Acquired	750		0
Accumulated Amortization, beginning of period	(86,005)		(79,179)
Amortization expense	(3,079)	(3,172)	(3,948)
Accumulated Amortization, end of period	(79,238)	$ (86,005)	(83,127)
Net CDI and CRI, end of period	21,312		34,446
Finite Lived Intangible Assets Fully Amortized Portion	$ 9,846		$ 0