Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2016
Income Taxes [Line Items]
Effective income tax rate from continuing operations	8.50%	5.10%
Income tax provision (benefit)	$ 1,968	$ 1,650
Internal Revenue Service (IRS)
Income Taxes [Line Items]
Minimum change in ownership percentage	50.00%
Measurement of change in ownership period	3 years
Minimum change in ownership percentage held by shareholders directly or indirectly	5.00%
Internal Revenue Service (IRS) | Minimum
Income Taxes [Line Items]
Income tax, years under examination			2014
The State of California Audit | Earliest Tax Year
Income Taxes [Line Items]
Income tax, years under examination	2013
The State of California Audit | Latest Tax Year
Income Taxes [Line Items]
Income tax, years under examination	2014