Goodwill and Other Intangible Assets - Roll Forward of Goodwill (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018
Goodwill [Roll Forward]
Balance at beginning of year		$ 287,446	$ 291,670
Additions	[1]	84,175	0
Other adjustments		0	(4,224)
Balance at End of Year		$ 371,621	$ 287,446

[1] Management is continuing to evaluate the purchase accounting fair value adjustments for the DNB merger. Any changes in preliminary estimates will be adjusted in goodwill in subsequent periods, but not extending beyond one year from the date of acquisition.