Stockholders' Equity - Schedule of Common Stock (Details) - shares		3 Months Ended		9 Months Ended
	Mar. 17, 2022	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued and outstanding, beginning balance (in shares)		62,087,303	65,864,116	65,968,224	66,456,663
Shares issued and outstanding, beginning balance (in shares)		62,087,303	65,864,116	65,968,224	66,456,663
Issuance of common stock for the acquisition of Zenefits (in shares)				193,221
Repurchase of common stock (in shares)	(3,653,690)	0	(230,456)	(4,419,423)	(1,155,707)
Awards effectively repurchased for required employee withholding taxes (in shares)		(78,718)	(47,764)	(176,514)	(165,383)
Shares issued and outstanding, ending balance (in shares)		62,229,506	65,743,170	62,229,506	65,743,170
Shares issued and outstanding, ending balance (in shares)		62,229,506	65,743,170	62,229,506	65,743,170
Issuance of common stock from vested restricted stock units
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock from vested restricted stock units (in shares)		199,171	127,704	496,051	474,222
Issuance of common stock from exercise of stock options
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock from exercise of stock options (in shares)		21,750	29,570	94,139	59,305
Issuance of common stock for employee stock purchase plan
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock for employee stock purchase plan (in shares)				73,808	74,070