Accrued Expenses - Accrued Expenses (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Payables And Accruals [Abstract]
Accrued wages	$ 65,423	$ 65,695
Accrued phone	43,919	39,537
Interest payable	33,918	35,702
Accrued other taxes (non-income related)	24,978	35,794
Other current liabilities	24,496	21,241
Income taxes payable	8,548	0
Customer credits	7,836	5,437
Accrued professional fees	6,474	5,436
Accrued employee benefit costs	4,578	5,839
Acquisition obligation for a net operating loss carryforward claim	3,573	3,573
Accrued lease expense	3,233	3,026
Outside commissions	2,967	2,922
Accrued licensing costs	1,982	669
Acquisition contingent consideration	1,864	0
Total	$ 233,789	$ 224,871