Goodwill and Other Intangible Assets - Finite-Lived Intangible Assets Roll Forward (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Gross Balance of CDI:
Balance, beginning of year	$ 145,212	$ 145,212	$ 125,945	$ 145,212	$ 125,945
Additions due to acquisitions	0	0	19,267	0	19,267
Balance, end of year	145,212	145,212	145,212	145,212	145,212
Accumulated amortization:
Balance, beginning of year	(63,848)	(59,705)	(46,596)	(59,705)	(42,633)
Amortization	(4,001)	(4,143)	(4,066)	(8,144)	(8,029)
Balance, end of year	(67,849)	(63,848)	(50,662)	(67,849)	(50,662)
Net intangible assets	$ 77,363	$ 81,364	$ 94,550	$ 77,363	$ 94,550	$ 85,500