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Commitments and Contingencies - Narrative (Details) - USD ($)
$ in Thousands
1 Months Ended 3 Months Ended 6 Months Ended
Nov. 08, 2017
May 31, 2017
Jun. 30, 2018
Jul. 01, 2017
Jun. 30, 2018
Jul. 01, 2017
Loss Contingencies [Line Items]            
Litigation settlement     $ 0 $ 7,000 $ 0 $ 7,000
1-800 Contacts Matter            
Loss Contingencies [Line Items]            
Amount of litigation settlement   $ 7,000        
Litigation settlement       $ 7,000    
Percent of settlement award deposited in escrow account (percent) 50.00%          
Amount of settlement deposited in escrow account $ 3,500