Background (Narrative) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) ft² store state	Dec. 31, 2017 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of stores | store		140
Number of states in which entity operates | state		31
Area of stores | ft²		20,200
Restricted cash	$ 855	$ 835	$ 855
Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Proceeds from restricted cash, financing activities	$ 6,000