Restructuring - Summary of Restructuring Charges (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Restructuring Cost and Reserve [Line Items]
Total Restructuring Expenses	$ 537	$ 845	$ 561	$ 14,617
Contractual Lease Obligations
Restructuring Cost and Reserve [Line Items]
Total Restructuring Expenses	586	694	1,512	12,011
Severance
Restructuring Cost and Reserve [Line Items]
Total Restructuring Expenses	0	(285)	601	1,306
Other Reversals
Restructuring Cost and Reserve [Line Items]
Total Restructuring Expenses	0	0	(1,176)	0
Gain on Sale of Closed Store Properties
Restructuring Cost and Reserve [Line Items]
Total Restructuring Expenses	(49)	0	(376)	0
Fixed Asset Impairment
Restructuring Cost and Reserve [Line Items]
Total Restructuring Expenses	$ 0	$ 436	$ 0	$ 1,300