Independent Investigation of the Audit Committee and Related Restatements (Schedule of Restated Unaudited EBITDA and EBITDA Reconciliation) (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2014	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Restated Unaudited EBITDA and EBITDA Reconciliation:
EBITDA - Continuing operations	$ 134,200	$ 104,200	$ 65,300	$ 169,500	$ 303,600	$ 403,700	$ 427,600	$ 322,100
Interest expense, net	(12,643)	(12,949)	(12,003)	(24,952)	(37,595)	(50,769)	(46,442)	(37,376)
Depreciation and amortization	(41,747)	(36,755)	(33,494)	(70,249)	(111,996)	(154,452)	(140,926)	(91,958)
Income from continuing operations before income taxes	79,764	54,499	19,753	74,252	154,016	$ 198,430	$ 240,214	$ 192,719
As Reported [Member]
Restated Unaudited EBITDA and EBITDA Reconciliation:
EBITDA - Continuing operations	128,200	101,500	71,600	173,100	301,200
Interest expense, net	(12,643)	(12,949)	(12,003)	(24,952)	(37,595)
Depreciation and amortization	(41,747)	(36,755)	(33,494)	(70,249)	(111,996)
Income from continuing operations before income taxes	73,772	51,777	26,106	77,884	151,655
Adjustments [Member]
Restated Unaudited EBITDA and EBITDA Reconciliation:
EBITDA - Continuing operations	6,000	2,700	(6,400)	(3,600)	2,400
Interest expense, net	0	0	0	0	0
Depreciation and amortization	0	0	0	0	0
Income from continuing operations before income taxes	$ 5,992	$ 2,722	$ (6,353)	$ (3,632)	$ 2,361