Borrowings (Summary Of Advances Payable To The Federal Home Loan Bank) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Federal Home Loan Bank, Advances, Maturity, Rolling Year [Abstract]
FHLB advances maturing within 1 year, Total Outstanding	$ 2,025,934	$ 2,275,000
FHLB advances maturing after 1 but within 2 years, Total Outstanding	500	145,934
FHLB advances maturing after 2 but within 3 years, Total Outstanding	200,000	500
FHLB advances maturing after 3 but within 4 years, Total Outstanding	103,026	200,000
FHLB advances maturing after 4 but within 5 years, Total Outstanding	175,000	78,026
FHLB advances maturing after 5 years, Total Outstanding	159,655	159,934
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances	2,664,115	2,859,394
Debt Instrument, Unamortized Premium	24	37
Federal Home Loan Bank advances	$ 2,664,139	$ 2,859,431
Federal Home Loan Bank, Advances, Weighted Average Interest Rate [Abstract]
FHLB advances maturing within 1 year, Weighted-Average Contractual Coupon Rate (as a percent)	0.55%	0.23%
FHLB advances maturing after 1 but within 2 years, Weighted-Average Contractual Coupon Rate (as a percent)	5.66%	1.80%
FHLB advances maturing after 2 but within 3 years, Weighted-Average Contractual Coupon Rate (as a percent)	1.36%	5.66%
FHLB advances maturing after 3 but within 4 years, Weighted-Average Contractual Coupon Rate (as a percent)	1.54%	1.36%
FHLB advances maturing after 4 but within 5 years, Weighted-Average Contractual Coupon Rate (as a percent)	1.77%	1.95%
FHLB advances maturing after 5 years, Weighted-Average Contractual Coupon Rate (as a percent)	1.60%	1.27%
Federal Home Loan Bank, Advances, Weighted Average Interest Rate (as a percent)	0.79%	0.50%