Consolidated Statements of Financial Condition (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Held to maturity, fair value	$ 1,670,951	$ 1,815,976
Preferred stock, par value (in usd per share)
Preferred stock, shares authorized (in shares)	30,000,000	30,000,000
Preferred stock, shares issued (in shares)	4,600,000	0
Common stock, par value (in usd per share)
Common stock, shares authorized (in shares)	332,023,233	332,023,233
Common stock, shares issued (in shares)	232,800,531	232,127,098
Treasury stock, shares (in shares)	10,651	16,123