Debt (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Long-Term Debt, Capital and Financing Leases and Financing Obligations [Line Items]
Debt	$ 6,173,483,000	$ 6,165,956,000
Less current portion	223,987,000	272,265,000
Long-term debt	5,949,496,000	5,893,691,000
Mortgage Notes Payable [Member]
Long-Term Debt, Capital and Financing Leases and Financing Obligations [Line Items]
Debt	3,140,091,000	3,105,410,000
Principal		316,300,000
Unamortized debt discount	55,700,000	59,600,000
Maturity date, start	Dec. 31, 2016
Maturity date, end	Dec. 31, 2017
Weighted average interest rate	4.82%	4.84%
Capital Lease Obligations [Member]
Long-Term Debt, Capital and Financing Leases and Financing Obligations [Line Items]
Debt	2,592,133,000	2,649,226,000
Maturity date, start	Dec. 31, 2030
Weighted average interest rate	8.25%	8.57%
Convertible Debt [Member]
Long-Term Debt, Capital and Financing Leases and Financing Obligations [Line Items]
Debt	275,198,000	272,345,000
Unamortized debt discount	41,100,000	43,900,000
Maturity date, start	Jun. 30, 2018
Weighted average interest rate	2.75%	2.75%
Construction Financing [Member]
Long-Term Debt, Capital and Financing Leases and Financing Obligations [Line Items]
Debt	65,588,000	50,118,000
Maturity date, start	Dec. 31, 2017
Maturity date, end	Dec. 31, 2019
Weighted average interest rate	5.04%	4.90%
Notes Payable, Insurance Premiums [Member]
Long-Term Debt, Capital and Financing Leases and Financing Obligations [Line Items]
Debt	16,124,000	22,586,000
Maturity date, start	Dec. 31, 2015
Weighted average interest rate	2.82%	2.82%
Other Notes Payable [Member]
Long-Term Debt, Capital and Financing Leases and Financing Obligations [Line Items]
Debt	$ 84,349,000	$ 66,271,000
Maturity date, start	Dec. 31, 2015
Maturity date, end	Dec. 31, 2020
Weighted average interest rate	5.52%	4.75%