Recent Accounting and Regulatory Pronouncements - Narrative (Details) - USD ($) $ in Thousands			3 Months Ended
		Jan. 01, 2020	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Impairment of goodwill			$ 0
Impairment of other intangible			0
Additional allowance for credit losses for loans			144,785	$ 56,927	$ 56,522	$ 55,798
Deferred tax assets			46,365	$ 31,316	$ 31,884
Additional reserve for unfunded commitments			$ 8,600
ASU 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Additional allowance for credit losses for loans	[1]	$ 54,438
Deferred tax assets	[2]	12,639
Additional reserve for unfunded commitments		6,400
Adjustment to retained earnings		$ 44,800

[1] This is the calculated adjustment to the ACL related to the adoption of ASC 326. Additional reserve related to non-acquired loans was $34,049, to acquired loans was $16,981 and to purchased credit deteriorated loans was $3,408.

[2] This is the effect of deferred tax assets related to the adjustment to the ACL from the adoption of ASC 326 using a 22% tax rate.