CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Common Stock and Additional Paid-In Capital	Retained Earnings	Treasury Stock	AOCI, net of tax
BALANCE (in shares) at Dec. 31, 2014		143,582,229
BALANCE at Dec. 31, 2014	$ 2,856,111		$ 1,677,931	$ 1,604,141	$ (430,198)	$ 4,237
Increase (Decrease) in Stockholders' Equity
Net income	100,027			100,027
Other comprehensive income	9,318					9,318
Stock compensation costs	3,954		3,954
Tax benefit from stock compensation plans, net	3,145		3,145
Net activity of common stock pursuant to various stock compensation plans and agreements (in shares)		238,320
Net activity of common stock pursuant to various stock compensation plans and agreements	(4,858)		833		(5,691)
Common stock dividends	(28,934)			(28,934)
BALANCE (in shares) at Mar. 31, 2015		143,820,549
BALANCE at Mar. 31, 2015	2,938,763		1,685,863	1,675,234	(435,889)	13,555
BALANCE (in shares) at Dec. 31, 2015		143,909,233
BALANCE at Dec. 31, 2015	3,122,950		1,701,459	1,872,594	(436,162)	(14,941)
Increase (Decrease) in Stockholders' Equity
Net income	107,516			107,516
Other comprehensive income	12,883					12,883
Stock compensation costs	4,575		4,575
Tax benefit from stock compensation plans, net	986		986
Net activity of common stock pursuant to various stock compensation plans and agreements (in shares)		154,518
Net activity of common stock pursuant to various stock compensation plans and agreements	(3,054)		0		(3,054)
Common stock dividends	(29,075)			(29,075)
BALANCE (in shares) at Mar. 31, 2016		144,063,751
BALANCE at Mar. 31, 2016	$ 3,216,781		$ 1,707,020	$ 1,951,035	$ (439,216)	$ (2,058)