Debt Schedule of Interest Expense On Liability Components (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Debt Instrument [Line Items]
Amortization of the discount on the liability component	$ 0	$ 5,336	$ 10,099
Convertible Subordinated Debt [Member]
Debt Instrument [Line Items]
Contractual interest coupon	0	3,420	5,590
Amortization of the discount on the liability component	0	5,336	10,099
Total interest expense on convertible notes	$ 0	$ 8,756	$ 15,689