Stockholders' Equity - Additional Information (Detail) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Equity [Abstract]
Preferred stock authorized	5,000,000	5,000,000
Common stock repurchased and retired, shares	0	0	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0