Sale-Leasebacks of Real Estate (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) warehouse	Dec. 31, 2017 USD ($)	Jul. 31, 2013 warehouse	Sep. 30, 2010 USD ($)	Sep. 30, 2007 warehouse
Sale Leaseback Transaction [Line Items]
Number of warehouses | warehouse	11		11		11
Sale-leaseback financing obligations | $	$ 118,920	$ 121,516
1 warehouse – 2010
Sale Leaseback Transaction [Line Items]
Number of warehouses | warehouse	1
Interest Rate as of December 31, 2018	10.34%
Sale-leaseback financing obligations | $	$ 19,265	19,457		$ 19,200
11 warehouses – 2007
Sale Leaseback Transaction [Line Items]
Number of warehouses | warehouse	11
Sale-leaseback financing obligations | $	$ 99,655	$ 102,059
11 warehouses – 2007 | Minimum
Sale Leaseback Transaction [Line Items]
Interest Rate as of December 31, 2018	7.00%
11 warehouses – 2007 | Maximum
Sale Leaseback Transaction [Line Items]
Interest Rate as of December 31, 2018	19.59%