Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2017

Equity [Abstract]

Summary of Common Stock Reserved for Future Issuance

Shares of Class A common stock reserved for future issuance were as follows (in thousands):

	December 31, 2017
Preferred stock		100,000
Class B common stock		12,199
2013 Employee stock purchase plan		2,720
2013 Equity incentive plan:
Outstanding options and restricted stock unit awards		9,567
Available for future grants		10,391
		134,877