Sale-Leasebacks of Real Estate (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018 USD ($) warehouse	Dec. 31, 2017 USD ($)
Sale Leaseback Transaction [Line Items]
Total sale-leaseback financing obligations	$ 120,289	$ 121,516
1 warehouse – 2010
Sale Leaseback Transaction [Line Items]
Number of warehouses | warehouse	1
Interest Rate as of June 30, 2018	10.34%
Total sale-leaseback financing obligations	$ 19,374	19,457
11 warehouses – 2007
Sale Leaseback Transaction [Line Items]
Number of warehouses | warehouse	11
Total sale-leaseback financing obligations	$ 100,915	$ 102,059
11 warehouses – 2007 | Minimum
Sale Leaseback Transaction [Line Items]
Interest Rate as of June 30, 2018	7.00%
11 warehouses – 2007 | Maximum
Sale Leaseback Transaction [Line Items]
Interest Rate as of June 30, 2018	19.59%