Accrued Expenses (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Payables and Accruals [Abstract]
Payroll and benefits	$ 60,907	$ 56,651
Deferred revenue and customer advances	48,637	52,773
Accrued royalties (Note 16)	33,324	33,324
Accrued interest	20,837	19,048
Income taxes payable	10,565	8,341
Accrued severance plan obligations (Note 13)	9,468	9,516
Other accrued expenses	34,107	33,311
Total accrued expenses	$ 217,845	$ 212,964