Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2012

Fair Value Disclosures [Abstract]

Fair Value, by Balance Sheet Grouping [Table Text Block]

The following table presents the carrying amount, estimated fair values and categorization under the fair value hierarchy of financial instruments held by the Company at June 30, 2012 and December 31, 2011, using market information and what the Company believes to be appropriate valuation methodologies under generally accepted accounting principles:

	June 30, 2012								December 31, 2011
Asset (liability)	Carrying Amount			Fair Value					Carrying Amount			Fair Value
				Level 1		Level 2						Level 1		Level 2
Cash and cash equivalents	$	189,103		$	189,103	$	—		$	78,603		$	78,603	$	—
Restricted cash	14,427			14,427		—			—			—		—
Current maturities of long-term debt	—			—		—			(28,110		)	—		(29,319		)
Long-term debt	(1,018,093		)	—		(1,185,347		)	(819,229		)	—		(994,851		)

Fair Value, Assets Measured on Recurring Basis [Table Text Block]

Assets measured at fair value on a recurring basis are summarized below:

Asset	Carrying Value at June 30, 2012		Level 2		Carrying Value at December 31, 2011		Level 2
Investment in special-purpose entity	$	2,690	$	2,690	$	2,690	$	2,690