Acquisitions (Schedule of Acquired Intangible Assets) (Details) - USD ($) $ in Thousands	Aug. 21, 2018	Feb. 22, 2017
SolarBOS
Acquired Finite-Lived Intangible Assets [Line Items]
Fair Value, finite-lived intangible assets acquired	$ 1,450
SolarBOS | Trademarks
Acquired Finite-Lived Intangible Assets [Line Items]
Fair Value, finite-lived intangible assets acquired	$ 300
Estimated Useful Life	3 years
SolarBOS | Technology
Acquired Finite-Lived Intangible Assets [Line Items]
Fair Value, finite-lived intangible assets acquired	$ 450
Estimated Useful Life	9 years
SolarBOS | Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Fair Value, finite-lived intangible assets acquired	$ 700
Estimated Useful Life	9 years
Package Concierge
Acquired Finite-Lived Intangible Assets [Line Items]
Fair Value, finite-lived intangible assets acquired		$ 3,600
Package Concierge | Technology
Acquired Finite-Lived Intangible Assets [Line Items]
Fair Value, finite-lived intangible assets acquired		$ 1,300
Estimated Useful Life		10 years
Package Concierge | Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Fair Value, finite-lived intangible assets acquired		$ 1,700
Estimated Useful Life		7 years
Trademarks | Package Concierge
Acquired Finite-Lived Intangible Assets [Line Items]
Fair Value, finite-lived intangible assets acquired		$ 600