Segment Reporting - Additional Information (Detail) $ in Thousands |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
|
Jun. 30, 2017
USD ($)
|
Jun. 30, 2016
USD ($)
|
Jun. 30, 2017
USD ($)
Segment
|
Jun. 30, 2016
USD ($)
|
Dec. 31, 2016
USD ($)
|
|
| Segment Reporting Information [Line Items] | |||||
| Number of reportable segments | Segment | 3 | ||||
| Revenues | $ 126,690 | $ 124,849 | $ 250,217 | $ 249,382 | |
| Assets | 2,021,774 | 2,021,774 | $ 2,004,894 | ||
| United States | |||||
| Segment Reporting Information [Line Items] | |||||
| Revenues | 104,800 | $ 103,100 | 207,400 | $ 206,200 | |
| Assets | $ 1,500,000 | $ 1,500,000 | $ 1,500,000 | ||