Goodwill and Identifiable Intangible Assets, Net - Remaining Weighted Average Useful Life of Definite Lived Intangible Assets (Detail)	12 Months Ended
	Dec. 31, 2017
Finite Lived Intangible Assets [Line Items]
Finite lived identifiable intangible assets, remaining weighted average useful lives	11 years 6 months
Customer relationships
Finite Lived Intangible Assets [Line Items]
Finite lived identifiable intangible assets, remaining weighted average useful lives	15 years 3 months 18 days
Trademarks and trade names
Finite Lived Intangible Assets [Line Items]
Finite lived identifiable intangible assets, remaining weighted average useful lives	14 years 6 months
Technology
Finite Lived Intangible Assets [Line Items]
Finite lived identifiable intangible assets, remaining weighted average useful lives	3 years 3 months 18 days
Customer Contracts
Finite Lived Intangible Assets [Line Items]
Finite lived identifiable intangible assets, remaining weighted average useful lives	3 years 8 months 12 days