Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jul. 18, 2015	Jul. 12, 2014	Jul. 18, 2015	Jul. 12, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net income		$ 51,760	$ 42,064	$ 113,149	$ 103,130
Pension and postretirement plans:
Amortization of prior service credit included in net income		(67)	(67)	(156)	(156)
Amortization of actuarial loss included in net income		624	191	1,456	446
Pension and postretirement plans, net of tax		557	124	1,300	290
Derivative instruments:
Net change in fair value of derivatives	[1]	5,818	(16,202)	1,390	(900)
Loss reclassified to net income		1,251	442	2,838	3,514
Derivative instruments, net of tax		7,069	(15,760)	4,228	2,614
Other comprehensive income (loss), net of tax		7,626	(15,636)	5,528	2,904
Comprehensive income		$ 59,386	$ 26,428	$ 118,677	$ 106,034

[1] Amounts in parentheses indicate debits to determine net income.