Fair Value Disclosures (Estimated Fair Values and Carrying Amounts of Assets and Liabilities) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, carrying value	$ 175,620,000	$ 223,394,000	$ 441,364,000	$ 80,120,000
Cash and cash equivalents, fair value	175,620,000	223,394,000
Restricted cash, carrying value	152,411,000	188,526,000
Restricted cash, fair value		188,526,000
Debt and other obligations, carrying amount	11,920,861,000	11,594,500,000
Debt and other obligations, fair value	12,286,161,000	11,892,587,000
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, carrying value	1
Restricted cash, carrying value	1
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt and other obligations, carrying amount	$ 2