Acquisition - Summary of Preliminary Estimated Fair Value of Intangible Assets Acquired and the Related Estimated Useful Lives (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2015
Business Acquisition [Line Items]
Intangible assets		$ 39,890
Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets		$ 39,890
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