Employee Benefit Plan (Details)	12 Months Ended
Dec. 31, 2012
Compensation and Retirement Disclosure [Abstract]
Eligible employee maximum contribution as a percentage of pre-tax compensation (in hundredths)	50.00%

The maximum amount of eligible employee compensation that can be contributed during a calendar year as a percentage of salary.

No definition available.

Name:	sfly_DefinedContributionPlanPercentageOfCompensationContributedMaximum
Namespace Prefix:	sfly_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration