STATEMENT OF CHANGES IN EQUITY - 9 months ended Sep. 30, 2016 - USD ($) $ in Thousands	Total	Common Stock [Member]	Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Shares issued, beginning balance at Dec. 31, 2015	52,598,005	52,598,005
Equity, beginning balance at Dec. 31, 2015	$ 1,841,555	$ 526	$ 1,764,875	$ 95,046	$ (14,491)	$ (4,401)
Net income	97,781	0	0	97,781	0	0
Other comprehensive income	347	0	0	0		347
Repurchase of common stock	(24,066)	$ 0	0	0	(24,066)	0
Common stock issued, shares		0
Common stock issued, value	1,650	$ 0	(16,593)	0	18,243	0
Common stock dividends - $1.05 per share	$ 54,923	$ 0	(683)	55,606	0	0
Shares issued, ending balance at Sep. 30, 2016	52,598,005	52,598,005
Equity, ending balance at Sep. 30, 2016	$ 1,862,344	$ 526	$ 1,748,965	$ 137,221	$ (20,314)	$ (4,054)