Other Assets, Other Long-term Liabilities and Other Income (Expense), Net (Other Income (Expense), Net) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Income (Expense), Net
Interest income	$ 4,793	$ 8,745	$ 2,842
Gain on sale of property used in operations			456
Adjustment of acquisition related liabilities	(5,972)	(26,374)	(256)
Amortization of deferred costs	(1,397)	(1,844)	(1,585)
Bank Fees	(1,236)	(1,559)	(2,090)
Realized loss on sale of investments, net	(1,851)	72	(2,699)
Miscellaneous Income (expense), net	(3,873)	2,385	1,475
Total other Income (Expense), net	$ (9,536)	$ (18,575)	$ (1,857)