Fair Value Measurements (Fair Value Of Long Term Debt) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012
Long-term debt, Fair Value	$ 1,262,211
Long-term debt, Carrying Value	1,207,243
Unamortized debt discount	34,165	[1]
Term Loan [Member]
Long-term debt, Fair Value	370,157
Long-term debt, Carrying Value	369,165
Revolving Credit Facility [Member]
Long-term debt, Fair Value	100,000
Long-term debt, Carrying Value	100,000
Convertible Senior Notes (Matures March 2025) [Member]
Long-term debt, Fair Value	159,408	[2]
Long-term debt, Carrying Value	157,830	[2]
Unamortized debt discount	1,200
Convertible Senior Notes (Matures March 2032) [Member]
Long-term debt, Fair Value	222,228	[3]
Long-term debt, Carrying Value	200,000	[3]
Unamortized debt discount	32,900
Senior Unsecured Notes [Member]
Long-term debt, Fair Value	288,021
Long-term debt, Carrying Value	274,960
MARAD Debt [Member]
Long-term debt, Fair Value	122,397	[4]
Long-term debt, Carrying Value	$ 105,288	[4]

[1] The notes will increase to their principal amount through accretion of non-cash interest charges through December 2012 for the Convertible Senior Notes due 2025 and through March 2018 for the Convertible Senior Notes due 2032.

[2] Amount excludes the related unamortized debt discount of $1.2 million.

[3] Amount excludes the related unamortized debt discount of $32.9 million.

[4] The estimated fair value of all debt, other than the MARAD debt, was determined using Level 1 inputs using the market approach. The fair value of the MARAD debt was determined using a third party evaluation of the remaining average life and outstanding principal balance of the MARAD indebtedness as compared to other governmental obligations in the marketplace with similar terms. The fair value of the MARAD Debt was estimated using Level 2 fair value inputs using the market approach.