Borrowings - Summary of Information Pertaining to Borrowings (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Long Term And Short Term Debt [Line Items]
Short-term borrowings, Balance	$ 258,427	$ 488,383
Long-term borrowings, Balance	116,037	115,933
Total Borrowings, Balance	$ 374,464	$ 604,316
Short-term borrowings, Weighted Average Rate	2.51%	2.57%
Long-term borrowings, Weighted Average Rate	3.68%	3.79%
Total Borrowings, Weighted Average Rate	2.87%	2.80%
Securities sold under repurchase agreements
Long Term And Short Term Debt [Line Items]
Short-term borrowings, Balance	$ 23,427	$ 18,383
Short-term borrowings, Weighted Average Rate	0.55%	0.46%
Short-term borrowings
Long Term And Short Term Debt [Line Items]
Short-term borrowings, Balance	$ 235,000	$ 470,000
Short-term borrowings, Weighted Average Rate	2.71%	2.65%
Long-term borrowings
Long Term And Short Term Debt [Line Items]
Long-term borrowings, Balance	$ 70,418	$ 70,314
Long-term borrowings, Weighted Average Rate	2.78%	2.84%
Junior subordinated debt securities
Long Term And Short Term Debt [Line Items]
Long-term borrowings, Balance	$ 45,619	$ 45,619
Long-term borrowings, Weighted Average Rate	5.07%	5.25%