Financing Arrangements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 25, 2016	Dec. 27, 2015
Short-term borrowings [Abstract]
Line of credit facility, available borrowing capacity	$ 700,000
Maturities of the notes, maximum	397 days
Commercial paper program, notes outstanding	$ 163,300	$ 160,000
Commercial paper program, weighted average interest rate	0.97%	0.61%
Unsecured Committed [Member]
Short-term borrowings [Abstract]
Maturity Date, Line of credit facility	Mar. 30, 2020
Line of credit facility, available borrowing capacity	$ 700,000
Commitment fee based on unused portion of line of credit facility	0.12%
Interest rate under line of credit facility	Eurocurrency Rate plus 1.125%.
Unsecured Uncommitted [Member]
Short-term borrowings [Abstract]
Line of credit facility, available borrowing capacity	$ 128,000
Weighted average interest rates of outstanding borrowings	8.17%	3.97%