Annual report pursuant to Section 13 and 15(d)

Cash Proceeds Along with Fair Value Disclosures Related to Grants, Exercises, and Vesting Options (Detail)

v3.10.0.1
Cash Proceeds Along with Fair Value Disclosures Related to Grants, Exercises, and Vesting Options (Detail) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]      
Proceeds from stock options exercised $ 2 $ 3 $ 1
Intrinsic value of stock options exercised [1]   $ 1  
Weighted-average fair value of options granted $ 1.38 $ 3.45 $ 5.15
Total fair value of shares vested during the year $ 1,191 $ 1,286 $ 1,728
[1] The intrinsic value of stock options exercised is the amount by which the market price of the stock on the date of exercise exceeded the market price of the stock on the date of grant.