Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Securities held-to-maturity ,fair value	$ 3,699,825	$ 3,370,912
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	3,000,000	3,000,000
Common stock par value	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	93,381,269	90,366,673
Treasury stock ,shares	3,292,072	3,407,256
Series A Preferred Stock [Member]
Preferred stock, shares issued	28,939	28,939
Preferred stock, shares outstanding	28,939	28,939
Series E Preferred Stock [Member]
Preferred stock, shares issued	5,060	5,060
Preferred stock, shares outstanding	5,060	5,060