Stock Plans (Narrative) (Details)	12 Months Ended
	Dec. 31, 2017 USD ($) plan $ / shares shares	Jan. 01, 2017 USD ($) $ / shares shares	Jan. 03, 2016 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Stock-based Compensation Plans | plan	1
Total income tax benefit recognized for stock-based compensation	$ 14,500,000	$ 10,500,000	$ 5,800,000
Stock-based compensation costs capitalized as part of inventory	300,000
Options related excess tax benefit, classified as a financing cash activity	0	0	2,435,000
Aggregate intrinsic value for stock options outstanding	$ 65,400,000
Weighted average remaining contractual term of options (in years)	4 years
Aggregate intrinsic value for stock options exercisable	$ 43,400,000
Weighted average remaining contractual term of options exercisable (in years)	2 years 11 months
Number of shares vested and expected to vest in the future | shares	2,200,000
Aggregate intrinsic value of vested and expected to vest stock options	$ 65,400,000
Weighted average remaining contractual term for options vested and expected to vest	4 years 1 month
Total pre-tax stock-based compensation expense	$ 25,421,000	$ 17,158,000	$ 17,278,000
Deferred compensation liability	$ 11,700,000
Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant-date fair value of stock granted (per share) | $ / shares	$ 52.69	$ 42.79	$ 46.83
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period | shares	15,139	19,584	8,860
Total pre-tax stock-based compensation expense	$ 8,700,000	$ 2,700,000	$ 4,000,000
Shares/units granted | shares	49,845	72,164	66,509
Awards/units outstanding | shares	164,481
Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant-date fair value of stock granted (per share) | $ / shares	$ 63.14	$ 54.58	$ 51.01
Total pre-tax stock-based compensation expense	$ 800,000	$ 800,000
Shares/units granted | shares	1,598	1,821	1,953
Stock award program for non-employees Directors, fair market value	$ 100,000	$ 100,000
Stock Awards [Member] | New Non-employee Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares/units granted | shares	820
Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant-date fair value of stock granted (per share) | $ / shares	$ 54.75
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period | shares	27,000
Fair value of restricted stock awards vested	$ 10,600,000	8,400,000	$ 7,800,000
Total pre-tax stock-based compensation expense	10,300,000	$ 9,300,000	$ 8,400,000
Total unrecognized compensation cost, net of estimated forfeitures, related to nonvested stock, granted	$ 13,200,000
Shares/units granted | shares	231,000
Awards/units outstanding | shares	496,000	521,000
Weighted-average period for recognition of unrecognized compensation cost, years	1 year 4 months
Option vesting period (in years)	3 years
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized under plan | shares	5,000,000
Weighted-average grant-date fair value of stock granted (per share) | $ / shares	$ 67.09	$ 49.67	$ 47.08
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Purchase Date	95.00%
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate	10.00%
Shares/units granted | shares	36,769	49,578	78,294
Shares available for grant under employee stock purchase plan | shares	900,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant-date fair value of options | $ / shares	$ 11.83	$ 10.20	$ 11.02
Total intrinsic value of options exercised	$ 17,600,000	$ 16,600,000	$ 25,900,000
Cash received from option exercises	18,000,000	14,400,000	14,900,000
Total pre-tax stock-based compensation expense	4,700,000	$ 4,400,000	$ 4,100,000
Total unrecognized compensation cost, net of estimated forfeitures, related to nonvested stock, granted	$ 6,000,000
Weighted-average period for recognition of unrecognized compensation cost, years	2 years
Option vesting period (in years)		3 years
Stock Options Expiration Period After Date of Grant		7 years
Performance Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant-date fair value of stock granted (per share) | $ / shares	$ 52.78
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period | shares	0
Total pre-tax stock-based compensation expense	$ 900,000
Shares/units granted | shares	54,337
Awards/units outstanding | shares	54,337
Two Thousand Nine Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized under plan | shares	10,000,000