Acquisitions (Zhongli) - Additional Information (Detail) - USD ($)		12 Months Ended
	Dec. 15, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Earn out expenses		$ 24,213,000	$ 32,670,000	$ 24,268,000
Adjustments to fair value of earn-out payable		4,218,000	11,222,000
Earn-out settled through exchange of accounts receivable		3,272,000
Zhongli [Member]
Business Acquisition [Line Items]
Equity interests acquired	100.00%
Consideration paid in cash for acquisition	$ 7,000,000
Earn out expenses	0	21,943,000	26,951,000	16,997,000
Adjustments to fair value of earn-out payable	$ 17,100,000	6,485,000	11,222,000
Earn-out settled through exchange of accounts receivable		3,200,000
Revenue from acquired entity		30,400,000	28,200,000	100,000
Income (loss) from acquired entity		$ (2,100,000)	$ (6,000,000)	$ 0