Income Taxes - Components of Deferred Taxes (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred income tax assets:
Net operating loss carryforwards	$ 107,813	$ 111,288
Compensation and benefit plans	47,204	44,813
Accrued expenses	30,693	28,179
Deferred Revenue	14,076	10,984
Tax credits	13,882	13,882
Foreign currency translation	0	2,183
Allowance for doubtful accounts	3,045	3,796
Reserves not currently deductible for tax purposes	4,258	4,404
Gross deferred income tax assets	220,971	219,529
Less valuation allowance	(102,590)	(100,205)
Total deferred income tax assets	118,381	119,324
Deferred income tax liabilities:
Acquired intangibles amortization	136,639	139,137
Foreign earnings	18,373	33,597
Excess tax depreciation over financial depreciation	44,401	42,634
Prepaid expenses	7,383	7,553
Other	412	625
Foreign currency translation	37	0
Total deferred income tax liabilities	207,245	223,546
Net deferred income tax liability	$ 88,864	$ 104,222