Borrowings Borrowings (Summary Of Advances Payable To the Federal Home Loan Bank) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Federal Home Loan Bank, Advances, Maturity, Rolling Year [Abstract]
FHLB advances maturing within 1 year, Total Outstanding	$ 1,109,295	$ 1,403,026
FHLB advances maturing after 1 but within 2 years, Total Outstanding	75,000	215,000
FHLB advances maturing after 2 but within 3 years, Total Outstanding	150,036	200,000
FHLB advances maturing after 3 but within 4 years, Total Outstanding	181	150
FHLB advances maturing after 4 but within 5 years, Total Outstanding	50,150	242
FHLB advances maturing after 5 years, Total Outstanding	8,187	8,390
Federal Home Loan Bank, Advances	$ 1,392,849	$ 1,826,808
Federal Home Loan Bank, Advances, Weighted Average Interest Rate [Abstract]
FHLB advances maturing within 1 year, Weighted Average Contractual Coupon Rate (as a percent)	2.07%	2.55%
FHLB advances maturing after 1 but within 2 years, Weighted Average Contractual Coupon Rate (as a percent)	1.51%	1.73%
FHLB advances maturing after 2 but within 3 years, Weighted Average Contractual Coupon Rate (as a percent)	3.03%	3.16%
FHLB advances maturing after 3 but within 4 years, Weighted Average Contractual Coupon Rate (as a percent)	1.71%	0.00%
FHLB advances maturing after 4 but within 5 years, Weighted Average Contractual Coupon Rate (as a percent)	1.59%	2.95%
FHLB advances maturing after 5 years, Weighted Average Contractual Coupon Rate (as a percent)	2.65%	2.65%
Federal Home Loan Bank, Advances, Weighted Average Contractual Coupon Rate (as a percent)	2.13%	2.52%
Pledged Financial Instruments, Not Separately Reported, Loans Receivable, for Federal Home Loan Bank Debt	$ 7,208,616	$ 6,689,761
Remaining borrowing capacity	$ 3,393,626	$ 2,568,664