Consolidated Statements of Condition (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Held-to-Maturity, Fair Value	$ 3,827,527	$ 4,006,412
Common Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common Stock, authorized shares	500,000,000	500,000,000
Common Stock, issued shares	57,856,672	57,749,071
Common Stock, outstanding shares	42,635,978	43,282,153
Treasury Stock, Shares	15,220,694	14,466,918