Quarterly report pursuant to Section 13 or 15(d)

Equity Method Investments - Additional Information (Detail)

v3.7.0.1
Equity Method Investments - Additional Information (Detail) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Equity [Abstract]        
Income (loss) from equity method investments $ 8,377 $ 1,076 $ 12,548 $ 1,346