Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Securities held to maturity, fair value	$ 2,104,782	$ 1,643,416
Unearned income on loans	$ 60,268	$ 51,642
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, liquidation preference per share	$ 1,000	$ 1,000
Preferred stock, shares authorized	20,000,000	20,000,000
Preferred stock, shares issued	110,877	110,877
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	211,406,626	176,595,060
Treasury stock, shares	1,286,025	1,153,390