Annual report pursuant to Section 13 and 15(d)

Employee Benefits (Details)

v3.8.0.1
Employee Benefits (Details)
shares in Thousands, $ in Thousands
 1 Months Ended 12 Months Ended
Mar. 31, 2017
shares
Mar. 31, 2016
shares
Dec. 30, 2017
USD ($)
Plan
Dec. 31, 2016
USD ($)
Jan. 02, 2016
USD ($)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]          
Number of defined contribution retirement plans | Plan     2    
Defined Contribution Plan, Employer Discretionary Contribution Amount     $ 3,290 $ 1,938 $ 2,757
Defined Contribution Benefit Plan Supplemental Pension Benefits Amount     $ 328 369 416
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent     100.00%    
Employee Stock Ownership Plan (ESOP), Shares Contributed to ESOP | shares 16,241 44,509      
Employee Stock Ownership Plan (ESOP), Compensation Expense     $ 1,016 567 1,432
Defined Benefit Contribution Plan Foreign Operations Expenses Recognized     $ 166 $ 199 $ 336
United Kingdom [Member]          
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]          
Stock Issued During Period, Shares, Employee Stock Ownership Plan | shares 775 3,547      
Germany [Member]          
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]          
Stock Issued During Period, Shares, Employee Stock Ownership Plan | shares   2,561