Investment in Non-Consolidated Joint Venture - Summarized Balance Sheet Information for Joint Venture (Detail) - Joint Venture [Member] - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Current assets	$ 40,712	$ 31,295
Non-current assets	24,386	22,522
Total assets	65,098	53,817
Current liabilities	16,522	13,549
Non-current liabilities	6
Total liabilities	$ 16,528	$ 13,549