Carrying Amount of Goodwill (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill [Line Items]
Goodwill acquired (disposed), net	$ 318,034,000	$ 989,437,000
Impairment	(51,200,000)	0	$ 0
Currency translation		10,423,000
Other	(4,491,000)	2,346,000
Balance as of end of period	2,278,512,000	2,016,169,000
Goodwill	2,708,368,000	2,394,825,000	1,392,619,000
Accumulated impairment losses	(429,856,000)	(378,656,000)	(378,656,000)
CPE
Goodwill [Line Items]
Goodwill acquired (disposed), net		698,106,000
Currency translation		10,483,000
Other	(4,491,000)
Balance as of end of period	1,386,680,000	1,391,171,000
Goodwill	1,386,680,000	1,391,171,000	682,582,000
N & C
Goodwill [Line Items]
Goodwill acquired (disposed), net		291,331,000
Impairment	(51,200,000)
Currency translation		(60,000)
Other		2,346,000
Balance as of end of period	573,798,000	624,998,000
Goodwill	1,003,654,000	1,003,654,000	710,037,000
Accumulated impairment losses	(429,856,000)	$ (378,656,000)	$ (378,656,000)
Enterprise
Goodwill [Line Items]
Goodwill acquired (disposed), net	318,034,000
Balance as of end of period	318,034,000
Goodwill	$ 318,034,000