Long-Term Debt (Schedule of Interest Expense Related to Convertible Notes) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended		3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 Convertible senior notes due December 2020 [Member]	Jun. 30, 2013 Convertible senior notes due December 2020 [Member]	Jun. 30, 2014 Convertible senior notes due December 2020 [Member]
Debt Instrument [Line Items]
Cash interest per contractual coupon rate			$ 719		$ 1,438
Amortization of note discount			2,167		4,315
Amortization of deferred financing costs	5,447	460	129		254
Total interest expense related to Convertible Notes			$ 3,015		$ 6,007