Quarterly report pursuant to Section 13 or 15(d)

Revenue - Narrative (Details)

v3.19.1
Revenue - Narrative (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 30, 2019
Mar. 31, 2018
Jan. 01, 2019
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]      
Contract Liabilities $ 31,329   $ 27,347
Revenue recognized included in contract liability balance $ 8,200 $ 3,200  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-09-30      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]      
Period of recognition 3 months    
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]      
Remaining performance obligation $ 335,500    
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]      
Remaining performance obligation $ 400,200