Condensed Parent Company Information - Condensed Statements of Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Income From subsidiaries
Income tax benefit	$ 38,304	$ 66,465	$ 52,510
Net income	131,461	175,722	163,356
Hancock [Member]
Operating Income From subsidiaries
Cash dividends received from bank subsidiaries	31,000	124,000	249,000
Dividends received from non-bank subsidiaries			2,990
Equity in earnings of subsidiaries greater than (less than) dividends received	111,424	58,358	(82,203)
Total operating income	142,424	182,358	169,787
Other expense, net	(17,297)	(10,035)	(10,335)
Income tax benefit	(6,334)	(3,399)	(3,904)
Net income	$ 131,461	$ 175,722	$ 163,356