Other Noncurrent Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other	$ 6,943	$ 5,611
Other noncurrent liabilities	38,505	140,833
Tax amortization benefit contingency
Contingent consideration	31,562	132,724
Deferred acquisition payment
Deferred revenue - non-current	$ 0	$ 2,498