Debt and Commitments (Details 3) (Convertible Debt [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Debt Instrument [Line Items]
Debt Instrument, Convertible, Interest Expense	$ 4,269	$ 4,089	$ 5,261
Coupon [Member] | 3.375% Convertible Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Convertible, Interest Expense	1,878	1,878	1,878
Coupon [Member] | 3.75% Convertible Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Convertible, Interest Expense	0	0	1,225
Debt discount amortization [Member] | 3.375% Convertible Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Convertible, Interest Expense	2,391	2,211	2,044
Debt discount amortization [Member] | 3.75% Convertible Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Convertible, Interest Expense	$ 0	$ 0	$ 114