Accrued Expenses (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Payables and Accruals [Abstract]
Payroll and benefits	$ 75,909	$ 56,651
Deferred revenue and customer advances	44,764	52,773
Accrued royalties (Note 19)	43,324	33,324
Accrued interest	21,807	19,048
Acquisition payable (Note 3)	17,897	0
Income taxes payable	17,528	8,341
Accrued severance plan obligations (Note 15)	11,197	9,516
Other accrued expenses	31,826	33,311
Total accrued expenses	$ 264,252	$ 212,964