Acquisition - Summary of Preliminary Estimated Fair Value of Intangible Assets Acquired and the Related Estimated Useful Lives (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($)
Business Acquisition [Line Items]
Intangible assets	$ 39,876
Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets	$ 39,876
Customer Relationships [Member] | Minimum [Member]
Business Acquisition [Line Items]
Useful Lives (in Years)	14 years
Customer Relationships [Member] | Maximum [Member]
Business Acquisition [Line Items]
Useful Lives (in Years)	20 years