Goodwill and Other Intangible Assets - Rollforward of Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Finite-lived Intangible Assets [Roll Forward]
CDI and CRI Balance, beginning of period	$ 109,646		$ 119,497	$ 117,573	$ 119,497
CDI and CRI Balance, end of period	109,646	$ 109,646	117,573	109,646	117,573
Accumulated Amortization, beginning of period	(79,082)		(72,117)	(79,179)	(62,377)
Amortization	(3,751)	(3,882)	(4,833)	(11,581)	(14,573)
Accumulated Amortization, end of period	(82,833)	$ (79,082)	(75,026)	(82,833)	(75,026)
Net CDI and CRI, end of period	26,813		42,547	26,813	42,547
Finite Lived Intangible Assets Fully Amortized Portion	$ 0		$ 1,924	$ 7,927	$ 1,924