Segments and Related Information (Reconciliation of EBITDA to Consolidated Income) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Less:
Interest expense, net	$ (46,442,000)	$ (37,376,000)	$ (34,466,000)
Depreciation and amortization	(140,928,000)	(92,601,000)	(75,228,000)
Income from continuing operations before income taxes	240,214,000	192,719,000	159,280,000
Continuing Operations [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
EBITDA	427,600,000	322,100,000	267,900,000
Less:
Interest expense, net	(46,400,000)	(37,400,000)	(34,500,000)
Depreciation and amortization	$ (140,926,000)	$ (91,958,000)	$ (74,151,000)