Summary of Potential Number of Shares that Could Vest Under Restricted Stock Unit Awards (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2020 USD ($) shares
Disclosure Of Restricted Stock Unit [Abstract]
Number of shares vesting at IRR of at least 6% | shares	190,707
Number of shares vesting at IRR of at least 8% | shares	286,060
Number of shares vesting at IRR of at least 14% | shares	436,681
Value at grant at IRR of at least 6% | $	$ 6,125
Value at grant at IRR of at least 8% | $	9,188
Value at grant at IRR of at least 14% | $	$ 14,026