Condensed Consolidating Financial Statements of Guarantors of Senior Notes and Senior Convertible Notes Condensed Consolidating Financial Statements of Guarantors Narrative (Details) (Unsecured Debt [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
April 2019 [Member]
Debt Instrument, Redemption [Line Items]
Senior Notes	$ 200,000	$ 0
July 2014 [Member]
Debt Instrument, Redemption [Line Items]
Convertible Debt	85,256	0
July 2016 [Member]
Debt Instrument, Redemption [Line Items]
Convertible Debt	$ 46,279	$ 0