Borrowings - Summary of Information Pertaining to Borrowings (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Long Term And Short Term Debt [Line Items]
Short-term borrowings	$ 656,987	$ 710,832
Long-term borrowings	59,737	60,332
Total Borrowings	$ 716,724	$ 771,164
Short-term borrowings, Weighted Average Rate	0.83%	0.70%
Long-term borrowings, Weighted Average Rate	3.43%	3.30%
Total Borrowings, Weighted Average Rate	1.05%	0.90%
Securities Sold under Repurchase Agreements
Long Term And Short Term Debt [Line Items]
Short-term borrowings	$ 46,987	$ 50,832
Short-term borrowings, Weighted Average Rate	0.01%	0.01%
Short-Term Borrowings
Long Term And Short Term Debt [Line Items]
Short-term borrowings	$ 610,000	$ 660,000
Short-term borrowings, Weighted Average Rate	0.89%	0.76%
Other Long-Term Borrowings
Long Term And Short Term Debt [Line Items]
Long-term borrowings	$ 14,118	$ 14,713
Long-term borrowings, Weighted Average Rate	2.92%	2.91%
Junior Subordinated Debt Securities
Long Term And Short Term Debt [Line Items]
Long-term borrowings	$ 45,619	$ 45,619
Long-term borrowings, Weighted Average Rate	3.59%	3.42%