Goodwill - Goodwill by Reportable Segment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Goodwill [Line Items]
Goodwill, gross, Beginning balance	$ 2,979,300
Foreign exchange	11,100
Goodwill, gross, Ending balance	2,990,400
Accumulated impairment charges, Beginning balance	(211,000)
Accumulated impairment charges, Ending balance	(211,000)
Goodwill, net	2,779,416	$ 2,768,304
CCS [Member]
Goodwill [Line Items]
Goodwill, gross, Beginning balance	2,077,500
Foreign exchange	9,800
Goodwill, gross, Ending balance	2,087,300
Accumulated impairment charges, Beginning balance	(51,500)
Accumulated impairment charges, Ending balance	(51,500)
Goodwill, net	2,035,800
CMS [Member]
Goodwill [Line Items]
Goodwill, gross, Beginning balance	901,800
Foreign exchange	1,300
Goodwill, gross, Ending balance	903,100
Accumulated impairment charges, Beginning balance	(159,500)
Accumulated impairment charges, Ending balance	(159,500)
Goodwill, net	$ 743,600