Consolidated Balance Sheet (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Pledged securities that can be sold or repledged	$ 1,856,326	$ 2,136,712
Investment securities, available for sale, amortized cost	11,551,614	12,138,636
Investment securities, held to maturity, fair value	2,456,097	2,864,147
Other, fair value	$ 461,057	$ 554,059
Preferred stock, par value	$ 1.00	$ 1.00
Preferred stock, shares authorized	1,000,000	1,000,000
Common stock, par value	$ 0.50	$ 0.50
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	159,950,278	159,563,512
Common stock issuable, shares	33,748	36,644
Treasury stock, shares	4,997,089
Series A and Series C [Member]
Preferred stock, shares issued	731,500	731,500
Preferred stock, shares outstanding	731,500	731,500
Preferred stock, liquidation preference per share	$ 1,000	$ 1,000
Series D Preferred Stock [Member]
Preferred stock, shares issued	50,000	50,000
Preferred stock, shares outstanding	50,000	50,000
Preferred stock, liquidation preference per share	$ 10,000	$ 10,000