Fair Value Measurements (Reconciliation of Beginning and Ending Level 3 Net Liabilities) (Details) - USD ($) |
3 Months Ended | 9 Months Ended | ||
---|---|---|---|---|
Sep. 30, 2018 |
Oct. 01, 2017 |
Sep. 30, 2018 |
Oct. 01, 2017 |
|
Fair Value Disclosures [Abstract] | ||||
Balance beginning of period | $ (74,093,000) | $ (64,076,000) | $ (65,328,000) | $ (63,201,000) |
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Purchases | 5,800,000 | 0.000 | 7,500,000 | 0.000 |
Payments | 16,507,000 | 0 | 16,507,000 | 34,000 |
Change in fair value (included within selling, general and administrative expenses) | (3,740,000) | (651,000) | (10,805,000) | (1,560,000) |
Balance end of period | $ (67,126,000) | $ (64,727,000) | $ (67,126,000) | $ (64,727,000) |