Stock-based Compensation - 2014 Employee Stock Purchase Plan (Detail) - 2014 Employee Stock Purchase Plan - shares		12 Months Ended
	May 02, 2014	Dec. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
For possible future issuance under employee stock purchase plan (in shares)	4,779
Common stock issuable period	10 years
Common stock outstanding percentage	0.80%
Employee stock purchase plan, number of shares, which might be added to common stock outstanding (in shares)	2,941
Number of shares of common stock for future issuance, board of directors prerogative, increase in period (in shares)	0
Common stock issued through employee stock purchase plan (in shares)		4,943	4,497
Share-based compensation arrangement by share-based payment award, number of additional shares authorized		2,941	2,941
Possible future issuance under equity compensation plan (in shares)		3,893	5,895