Acquisition (Details 2) (Central, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Oct. 02, 2012	Sep. 30, 2012
Fair values of the assets acquired and liabilities assumed
Net current liabilities		$ (25,444)
Leasehold improvements, equipment, land and construction in progress, net		24,781
Other noncurrent assets		17,748
Long-term debt		(237,223)
Unfavorable lease contracts		(101,676)
Other noncurrent liabilities		(19,523)
Net long-term deferred tax liability		(22,528)
Net liabilities assumed		(156,930)
Goodwill		306,599
Total consideration transferred		149,669	149,669
Amortization period for unfavorable lease contracts	7 years
Management contracts
Fair values of the assets acquired and liabilities assumed
Identified intangible assets:		81,000
Weighted average useful lives of identified intangible assets	16 years
Favorable lease contracts
Fair values of the assets acquired and liabilities assumed
Identified intangible assets:		80,235
Weighted average useful lives of identified intangible assets	10 years
Trade name / trademarks
Fair values of the assets acquired and liabilities assumed
Identified intangible assets:		9,100
Weighted average useful lives of identified intangible assets	4 years
Existing technology
Fair values of the assets acquired and liabilities assumed
Identified intangible assets:		34,000
Weighted average useful lives of identified intangible assets	4 years 6 months
Non-competition agreements
Fair values of the assets acquired and liabilities assumed
Identified intangible assets:		2,600
Weighted average useful lives of identified intangible assets	1 year
Preliminary amounts
Fair values of the assets acquired and liabilities assumed
Net current liabilities		(28,041)
Leasehold improvements, equipment, land and construction in progress, net		24,154
Other noncurrent assets		17,748
Long-term debt		(237,223)
Unfavorable lease contracts		(69,316)
Other noncurrent liabilities		(19,523)
Net long-term deferred tax liability		(24,516)
Net liabilities assumed		(152,567)
Goodwill		302,236
Total consideration transferred		149,669
Reclassification from net current liabilities to net long term deferred tax liability		24,434
Preliminary amounts | Management contracts
Fair values of the assets acquired and liabilities assumed
Identified intangible assets:		81,000
Preliminary amounts | Favorable lease contracts
Fair values of the assets acquired and liabilities assumed
Identified intangible assets:		51,650
Preliminary amounts | Trade name / trademarks
Fair values of the assets acquired and liabilities assumed
Identified intangible assets:		14,900
Preliminary amounts | Existing technology
Fair values of the assets acquired and liabilities assumed
Identified intangible assets:		34,000
Preliminary amounts | Non-competition agreements
Fair values of the assets acquired and liabilities assumed
Identified intangible assets:		$ 2,600