Revenues Revenues - Estimated and Accrued Variable Concideration (Details) - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2019	Jul. 01, 2018
Revenue from Contract with Customer [Abstract]
Accrued rebates	$ 24,178	$ 23,586
Accrued returns	13,249	8,676
Price adjustments recognized against gross accounts receivable	$ 29,762	$ 26,581

Amount of increase (decrease) in revenue recognized for cumulative catch-up adjustment from change in estimate of transaction price which increases (decreases) right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time. Includes, but is not limited to, change in assessment of whether estimate of variable consideration is constrained.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130551-203045

Name:	us-gaap_ContractWithCustomerAssetCumulativeCatchUpAdjustmentToRevenueChangeInEstimateOfTransactionPrice
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration