Quarterly report pursuant to Section 13 or 15(d)

Summary of Potential Number of Shares Vesting under Restricted Stock Unit Awards (Detail)

v3.8.0.1
Summary of Potential Number of Shares Vesting under Restricted Stock Unit Awards (Detail)
$ in Thousands
9 Months Ended
Sep. 30, 2017
USD ($)
shares
Disclosure Of Restricted Stock Unit [Abstract]  
Number of shares vesting at IRR of at least 7% | shares 58,545
Number of shares vesting at IRR of at least 9.5% | shares 117,089
Number of shares vesting at IRR of at least 13% | shares 175,634
Value at grant at IRR of at least 7% | $ $ 2,481
Value at grant at IRR of at least 9.5% | $ 4,961
Value at grant at IRR of at least 13% | $ $ 7,442