Goodwill and Other Intangible Assets - Summary of Finite-Lived Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount	$ 84,962	$ 84,962
Accumulated Amortization	(49,597)	(47,702)
Net Carrying Amount	35,365	37,260
Core deposit intangibles
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount	82,492	82,492
Accumulated Amortization	(48,449)	(46,599)
Net Carrying Amount	34,043	35,893
Customer relationship intangible
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount	2,470	2,470
Accumulated Amortization	(1,148)	(1,103)
Net Carrying Amount	$ 1,322	$ 1,367