Restructuring - Summary of Restructuring Charges (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Restructuring Cost and Reserve [Line Items]
Total Restructuring Expenses	$ (882)	$ 13,445	$ 24	$ 13,772
Contractual Lease Obligations
Restructuring Cost and Reserve [Line Items]
Total Restructuring Expenses	207	11,841	926	11,318
Employee Severance
Restructuring Cost and Reserve [Line Items]
Total Restructuring Expenses	87	1,144	601	1,590
Other Reversals
Restructuring Cost and Reserve [Line Items]
Total Restructuring Expenses	(1,176)	0	(1,176)	0
Gain on Sale of Closed Store Properties
Restructuring Cost and Reserve [Line Items]
Total Restructuring Expenses	0	0	(327)	0
Fixed Asset Impairment
Restructuring Cost and Reserve [Line Items]
Total Restructuring Expenses	$ 0	$ 460	$ 0	$ 864