Consolidated Statements of Condition (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Consolidated Statements of Condition
Held-to-Maturity, Fair Value (in dollars)	$ 3,828,954	$ 3,754,206
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	57,301,892	57,134,470
Common Stock, outstanding shares	45,248,277	45,947,116
Treasury Stock, Shares	12,053,615	11,187,354