Offsetting Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell [Member] | Assets [Member]
Offsetting Assets [Line Items]
Net amount	$ 1,587,212	$ 619,758
Gross amounts recognized	1,587,212	619,758
Gross amounts offset in the balance sheet	0	0
Net amounts presented in the balance sheet	1,587,212	619,758
Gross amounts not offset in the balance sheet	0	0
Cash Collateral Received/Pledged	0	0
Derivative Financial Instruments, Assets [Member] | Assets [Member]
Offsetting Assets [Line Items]
Net amount	103,041	71,722
Gross amounts recognized	125,363	77,638
Gross amounts offset in the balance sheet	0	0
Net amounts presented in the balance sheet	125,363	77,638
Gross amounts not offset in the balance sheet	(22,322)	$ (5,916)
Cash Collateral Received/Pledged	0
Assets, Total [Member] | Assets [Member]
Offsetting Assets [Line Items]
Net amount	1,690,253	$ 691,480
Gross amounts recognized	1,712,575	697,396
Gross amounts offset in the balance sheet	0	0
Net amounts presented in the balance sheet	1,712,575	697,396
Gross amounts not offset in the balance sheet	(22,322)	(5,916)
Cash Collateral Received/Pledged	0	0
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Member] | Other Liabilities [Member]
Offsetting Assets [Line Items]
Net amount	232,188	346,987
Gross amounts recognized	232,188	346,987
Gross amounts offset in the balance sheet	0	0
Net amounts presented in the balance sheet	232,188	346,987
Gross amounts not offset in the balance sheet	0	0
Cash Collateral Received/Pledged	0	0
Derivative Financial Instruments, Liabilities [Member] | Other Liabilities [Member]
Offsetting Assets [Line Items]
Net amount	10,998	5,518
Gross amounts recognized	104,469	72,568
Gross amounts offset in the balance sheet	0	0
Net amounts presented in the balance sheet	104,469	72,568
Gross amounts not offset in the balance sheet	(22,322)	(5,916)
Cash Collateral Received/Pledged	(71,149)	(61,134)
Liabilities, Total [Member] | Other Liabilities [Member]
Offsetting Assets [Line Items]
Net amount	243,186	352,505
Gross amounts recognized	336,657	419,555
Gross amounts offset in the balance sheet	0	0
Net amounts presented in the balance sheet	336,657	419,555
Gross amounts not offset in the balance sheet	(22,322)	(5,916)
Cash Collateral Received/Pledged	$ (71,149)	$ (61,134)