Intangible Assets, Net - Net Consolidated Balance of Amortizable Intangible Assets (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Useful Life (In Years)	10 years
Gross Carrying Amount	$ 25,002
Accumulated Amortization	(16,460)
Total amortizable intangible assets	$ 8,542	$ 10,803
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Useful Life (In Years)	10 years
Gross Carrying Amount	$ 25,002
Accumulated Amortization	(16,460)
Total amortizable intangible assets	$ 8,542