Summary of Significant Accounting Policies (Correction of an Immaterial Error to the Financial Statements (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Decrease in loans held-for-sale	$ (150,414)	$ (84,660)
Decrease in proceeds from sales of loans held for sale	(146,478)	(67,983)
Decrease in net change in other assets and liabilities	(21,803)	(11,956)
Decrease in net cash provided by operating activities	97,919	74,380
Loans and Leases	9,387,613	8,331,469	$ 8,949,785
Proceeds from Sales of Loans	112,357	19,055
Increase to net cash used in investing activities	(484,388)	(381,731)
Decrease in transfers from loans to loans held for sale	62,727	$ 101,282
Adjustment For Error Correction, YTD 2016 | Immaterial Error From Amounts Incorrectly Reported In Prior Period
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Decrease in loans held-for-sale	97,300
Decrease in proceeds from sales of loans held for sale	19,100
Decrease in net change in other assets and liabilities	100
Decrease in net cash provided by operating activities	78,100
Loans and Leases	97,200
Proceeds from Sales of Loans	19,100
Increase to net cash used in investing activities	78,100
Decrease in transfers from loans to loans held for sale	$ (2,300)