Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	May 23, 2019	Jun. 30, 2018
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Trading Symbol	wage
Entity Registrant Name	WAGEWORKS, INC.
Entity Central Index Key	0001158863
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth	false
Entity Emerging Growth	false
Entity Common Stock, Shares Outstanding		39,869,857
Entity Public Float			$ 1,992,642,850
Entity Current Reporting Status	No
Entity Voluntary Filers	No
Entity Well Known Seasoned Issuer	Yes
Entity Shell Company	false