Income Taxes - Components of Deferred Taxes (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred income tax assets:
Net operating loss carryforwards	$ 111,288	$ 123,777
Benefit plans	33,347	32,329
Accrued expenses	28,179	28,539
Tax credits	13,882	14,717
Foreign currency translation	2,183	10,851
Allowance for doubtful accounts	3,796	4,363
Reserves not currently deductible for tax purposes	4,404	3,552
Other	21,824	20,901
Gross deferred income tax assets	218,903	239,029
Less valuation allowance	(100,205)	(109,240)
Total deferred income tax assets	118,698	129,789
Deferred income tax liabilities:
Acquired intangibles amortization	139,137	150,482
Foreign earnings	33,597	33,869
Excess tax depreciation over financial depreciation	42,634	33,182
Prepaid expenses	7,553	10,005
Total deferred income tax liabilities	222,921	227,538
Net deferred income tax liability	104,223	97,749
Deferred income tax liabilities included in the balance sheet are:
Deferred income tax liability-current	1,693	1,117
Deferred income tax liability-long-term	102,530	96,632
Net deferred income taxes	$ 104,223	$ 97,749