Fair Value Measurements (Fair Value Of Assets Measured On A Recurring And Nonrecurring Basis) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Recurring Items [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Cash and cash equivalents	$ 107,798	$ 94,410
Recurring Items [Member] | Quoted Prices In Activated Markets For Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Cash and cash equivalents	107,798	94,410
Recurring Items [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Cash and cash equivalents	0	0
Recurring Items [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Cash and cash equivalents	0	0
Nonrecurring Items [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Assets held for sale	675	675
Nonrecurring Items [Member] | Quoted Prices In Activated Markets For Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Assets held for sale	0	0
Nonrecurring Items [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Assets held for sale	0	0
Nonrecurring Items [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Assets held for sale	675	675
Convertible Senior Notes [Member] | Recurring Items [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Senior Notes	272,800	248,000
Convertible Senior Notes [Member] | Recurring Items [Member] | Quoted Prices In Activated Markets For Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Senior Notes	272,800	248,000
Convertible Senior Notes [Member] | Recurring Items [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Senior Notes	0	0
Convertible Senior Notes [Member] | Recurring Items [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Senior Notes	0	0
Secured Senior Notes [Member] | Recurring Items [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Senior Notes	731,350	702,700
Secured Senior Notes [Member] | Recurring Items [Member] | Quoted Prices In Activated Markets For Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Senior Notes	731,350	702,700
Secured Senior Notes [Member] | Recurring Items [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Senior Notes	0	0
Secured Senior Notes [Member] | Recurring Items [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Senior Notes	$ 0	$ 0