v3.19.1
Related Party Transactions - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Related Party Transactions [Abstract]    
Expense from transactions with related party $ 8.2 $ 9.1
Payment to related party 8.7 8.6
Due to affiliate $ 1.0 $ 1.6