Segment Information - Additional Information (Detail) |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
|
Sep. 30, 2015
USD ($)
|
Sep. 30, 2014
USD ($)
|
Sep. 30, 2015
USD ($)
Segment
|
Sep. 30, 2014
USD ($)
|
|
| Segment Reporting Information [Line Items] | ||||
| Number of reportable segments | Segment | 2 | |||
| Revenues | $ 226,057,000 | $ 222,134,000 | $ 641,995,000 | $ 605,783,000 |
| Evolution1 [Member] | ||||
| Segment Reporting Information [Line Items] | ||||
| Revenues | $ 72,205 | |||