Quarterly report pursuant to Section 13 or 15(d)

Equity Method Investments - Additional Information (Details)

v3.10.0.1
Equity Method Investments - Additional Information (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Equity [Abstract]        
Income (loss) from equity method investments $ 11,671 $ 6,876 $ 19,969 $ 19,424