Commitments, Guarantees, and Contingent Liabilities (Details) - USD ($) $ in Thousands		Mar. 31, 2017	Dec. 31, 2016
Other Commitments [Line Items]
Letters of credit		$ 146,632	$ 100,430
Recourse on assets sold:
Unpaid principal balance of loans sold		185,101	187,158
Carrying value of recourse obligation	[1]	150	142
Commitments to extend credit
Other Commitments [Line Items]
Commercial, industrial, and agricultural		1,737,410	1,522,152
Commercial real estate		427,425	397,423
Home equity		486,880	426,384
Other commitments	[2]	250,123	214,943
Total commitments to extend credit		$ 2,901,838	$ 2,560,902

[1] Included in other liabilities in the Consolidated Statements of Financial Condition.

[2] Other commitments includes installment and overdraft protection program commitments.