Basis of Presentation and Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2017

Fair Value Disclosures [Abstract]

Fair Value, Assets And Liabilities

The following table represents the Company's assets and liabilities that are measured at fair value on a recurring basis at September 30, 2017 (in thousands):

					Quoted Prices
					in Active		Significant
					Markets		Other		Significant
					for Identical		Observable		Unobservable
			Total at		Assets		Inputs		Inputs
			September 30, 2017		(Level 1)		(Level 2)		(Level 3)
Assets:
	U.S. Treasury securities		$	548,010	$	-	$	548,010	$	-
	Foreign government securities			6,970		-		6,970		-
	Corporate debt securities			1,884,101		-		1,884,101		-
	Time deposits			403,112		-		403,112		-
	Equity securities			147		-		147		-
	Waters 401(k) Restoration Plan assets			33,845		33,845		-		-
	Foreign currency exchange contracts			213		-		213		-
		Total	$	2,876,398	$	33,845	$	2,842,553	$	-
Liabilities:
	Contingent consideration		$	3,017	$	-	$	-	$	3,017
	Foreign currency exchange contracts			63		-		63		-
		Total	$	3,080	$	-	$	63	$	3,017

The following table represents the Company's assets and liabilities that are measured at fair value on a recurring basis at December 31, 2016 (in thousands):

					Quoted Prices
					in Active		Significant
					Markets		Other		Significant
			Total at		for Identical		Observable		Unobservable
			December 31,		Assets		Inputs		Inputs
			2016		(Level 1)		(Level 2)		(Level 3)
Assets:
	U.S. Treasury securities		$	570,313	$	-	$	570,313	$	-
	Foreign government securities			17,991		-		17,991		-
	Corporate debt securities			1,643,838		-		1,643,838		-
	Time deposits			199,906		-		199,906		-
	Equity securities			147		-		147		-
	Waters 401(k) Restoration Plan assets			30,954		30,954		-		-
	Foreign currency exchange contracts			60		-		60		-
		Total	$	2,463,209	$	30,954	$	2,432,255	$	-
Liabilities:
	Contingent consideration		$	3,007	$	-	$	-	$	3,007
	Foreign currency exchange contracts			730		-		730		-
		Total	$	3,737	$	-	$	730	$	3,007

Summary of Derivative Instruments by Risk Exposure [Abstract]

Gains (Losses) on Foreign Exchange Contracts

The following is a summary of the activity included in cost of sales in the statements of operations related to the foreign currency exchange contracts (in thousands):

	Three Months Ended				Nine Months Ended
	September 30, 2017		October 1, 2016		September 30, 2017		October 1, 2016
Realized gains (losses) on closed contracts	$	2,871	$	(1,994)	$	3,301	$	(9,525)
Unrealized (losses) gains on open contracts		(1,258)		1,003		819		11
Cumulative net pre-tax gains (losses)	$	1,613	$	(991)	$	4,120	$	(9,514)

Fair Value of Forward Foreign Exchange Contracts

The Company's foreign currency exchange contracts included in the consolidated balance sheets are classified as follows (in thousands):

	September 30, 2017		December 31, 2016
Other current assets	$	213	$	60
Other current liabilities	$	63	$	730

Warranty Accrual Roll Forward [Abstract]

Warranty Accrual Roll Forward

The following is a summary of the activity of the Company's accrued warranty liability for the nine months ended September 30, 2017 and October 1, 2016 (in thousands):

	Balance at						Balance at
	Beginning		Accruals for		Settlements		End of
	of Period		Warranties		Made		Period
Accrued warranty liability:
September 30, 2017	$	13,391	$	6,287	$	(6,823)	$	12,855
October 1, 2016	$	13,349	$	7,101	$	(6,915)	$	13,535