CONSOLIDATED BALANCE SHEETS PARENTHETICAL - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Available for Sale at Fair value - Amortized cost	$ 28,322,977	$ 23,105,597
Preferred stock par value	$ 0.01	$ 0.01
Preferred stock shares authorized	10,000,000	10,000,000
Preferred stock shares issued	0	0
Preferred stock shares outstanding	0	0
Common stock par value	$ 0.01	$ 0.01
Common stock shares authorized	140,000,000	140,000,000
Common Stock, Shares, Issued	79,137,758	79,137,758
Common stock shares outstanding	65,204,526	68,772,961
Treasury Shares Held	13,933,232	10,364,797
Allowances for Loan and Lease Losses, Real Estate	$ 6,813	$ 6,471