Consolidated Statements of Shareholder's Equity Statement - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]
Common Stock, Shares, Outstanding		75,454,511
Stockholders' Equity Attributable to Parent	$ 2,008,681	$ 754	$ 1,468,779	$ 539,332	$ (184)
Stock Issued During Period, Shares, New Issues		276,923
Stock Issued During Period, Value, New Issues	0	$ 3	(3)
Stock Repurchased During Period, Shares		(653,796)
Stock Repurchased During Period, Value	(11,424)	$ (6)	(11,418)
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	2,410		2,410
APIC, Share-based Payment Arrangement, Restricted Stock Unit, Increase for Cost Recognition			796
Dividends, Common Stock, Cash	(22,518)			(22,518)
Net income (loss)	34,810			34,810
Net derivative loss reclassified into earnings	184				(184)
Proceeds from Contributions from Parent	0
Net income (loss)	65,922
Net derivative loss reclassified into earnings	184
Common Stock, Shares, Outstanding		75,077,638
Stockholders' Equity Attributable to Parent	2,012,939	$ 751	1,460,564	551,624	0
Stock Issued During Period, Shares, New Issues		35,000
Stock Issued During Period, Value, New Issues	0	$ 0	0
Stock Repurchased During Period, Shares		(129,524)
Stock Repurchased During Period, Value	(2,864)	$ (1)	(2,863)
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	2,833		2,833
Dividends, Common Stock, Cash	(22,536)			(22,536)
Net income (loss)	31,112			31,112
Net derivative loss reclassified into earnings	0
Common Stock, Shares, Outstanding		74,983,114
Stockholders' Equity Attributable to Parent	$ 2,021,484	$ 750	1,460,534	560,200	0
Common Stock, Shares, Outstanding	75,122,129	75,122,129
Stockholders' Equity Attributable to Parent	$ 2,052,684	$ 751	1,446,664	605,269	0
Proceeds from Contributions from Parent	25,536		25,536
Stock Issued During Period, Shares, New Issues		28,568
Stock Issued During Period, Value, New Issues	0	$ 1	(1)
Stock Repurchased During Period, Shares		(73,903)
Stock Repurchased During Period, Value	(2,370)	$ (1)	(2,369)
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	38,727		38,727
APIC, Share-based Payment Arrangement, Restricted Stock Unit, Increase for Cost Recognition	2,005		2,005
Dividends, Common Stock, Cash	(24,025)			(24,025)
Net income (loss)	(34,221)			(34,221)
Proceeds from Contributions from Parent	25,536
Net income (loss)	(225,198)
Net derivative loss reclassified into earnings	$ 0
Common Stock, Shares, Outstanding	14,048	14,048
Stockholders' Equity Attributable to Parent	$ 2,026,590	$ 0	1,485,777	540,813	0
Net income (loss)	(190,977)			(190,977)
Net derivative loss reclassified into earnings	$ 0
Common Stock, Shares, Outstanding	14,048	14,048
Stockholders' Equity Attributable to Parent	$ 1,835,613	$ 0	$ 1,485,777	$ 349,836	$ 0