Segments and Geographic Information - Company's Reportable Segments (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Segment Reporting Information [Line Items]
Revenues	$ 307,453	$ 320,498	$ 631,138	$ 644,927
Percentage of revenues	100.00%	100.00%	100.00%	100.00%
Depreciation, net	$ 11,007	$ 11,322	$ 22,066	$ 22,620
Amortization of intangibles	3,435	3,659	6,866	7,310
Income (loss) from operations	18,217	10,427	40,758	24,905
Other (expense), net	(626)	(714)	(1,728)	(319)
Income taxes	(4,679)	(1,376)	(10,479)	(5,936)
Net income	12,912	8,337	28,551	18,650
Total assets	928,569	945,949	928,569	945,949	$ 944,500
Operating Segments [Member] | Americas [Member]
Segment Reporting Information [Line Items]
Revenues	$ 249,682	$ 256,663	$ 513,855	$ 517,909
Percentage of revenues	81.20%	80.10%	81.40%	80.30%
Depreciation, net	$ 9,605	$ 10,107	$ 19,185	$ 20,248
Amortization of intangibles	3,435	3,659	6,866	7,310
Income (loss) from operations	28,669	21,135	61,210	43,782
Total assets	1,067,801	1,093,003	1,067,801	1,093,003
Operating Segments [Member] | EMEA [Member]
Segment Reporting Information [Line Items]
Revenues	$ 57,752	$ 63,835	$ 117,247	$ 127,018
Percentage of revenues	18.80%	19.90%	18.60%	19.70%
Depreciation, net	$ 1,084	$ 1,215	$ 2,227	$ 2,372
Income (loss) from operations	2,969	1,561	6,757	4,445
Total assets	1,394,836	$ 1,444,643	1,394,836	$ 1,444,643
Other Items [Member]
Segment Reporting Information [Line Items]
Revenues	$ 19		$ 36
Percentage of revenues	0.00%	0.00%	0.00%	0.00%
Depreciation, net	$ 318		$ 654
Income (loss) from operations	(13,421)	$ (12,269)	(27,209)	$ (23,322)
Other (expense), net	(626)	(714)	(1,728)	(319)
Income taxes	(4,679)	(1,376)	(10,479)	(5,936)
Total assets	$ (1,534,068)	$ (1,591,697)	$ (1,534,068)	$ (1,591,697)