Consolidated Statement of Shareholders' Equity - 3 months ended Mar. 31, 2016 - USD ($)	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Treasury Stock	Accumulated Other Comprehensive Income (Loss)
Beginning Balance at Dec. 31, 2015	$ 4,397,691,000	$ 1,228,000	$ 4,405,775,000	$ 13,907,000	$ (51,047,000)	$ 27,828,000
Shares outstanding, beginning balance (shares) at Dec. 31, 2015		121,413,727
Stockholders' Equity Disclosure [Rollforward]
Net earnings	90,456,000			90,456,000
Other comprehensive loss-net unrealized loss on securities available-for-sale, net of tax	20,651,000	$ 0	0	0	0	20,651,000
Restricted stock awarded and earned stock compensation, net of shares forfeited	5,046,000	$ 4,000	5,042,000	0	0	0
Restricted stock awarded and earned compensation, net of shares forfeited (shares)		362,254
Restricted stock surrendered	(141,000)	$ 0	0	0	(141,000)	0
Restricted stock surrendered (shares)		(4,729)
Tax effect from vesting of restricted stock	3,795,000	$ 0	3,795,000	0	0	0
Cash dividends paid	(60,906,000)	0	(60,906,000)	0	0	0
Ending Balance at Mar. 31, 2016	$ 4,456,592,000	$ 1,232,000	$ 4,353,706,000	$ 104,363,000	$ (51,188,000)	$ 48,479,000
Shares outstanding, ending balance (shares) at Mar. 31, 2016		121,771,252