Postretirement benefits other than pension (Tables) (Other Postretirement Benefit Plans, Defined Benefit [Member])

3 Months Ended

Mar. 31, 2013

Other Postretirement Benefit Plans, Defined Benefit [Member]

Defined Benefit Plan Disclosure [Line Items]

Postretirement benefit costs for health care and life insurance

Postretirement benefit costs for health care and life insurance are presented in the following table:

In thousands of dollars	Thirteen Weeks Ended
	Mar. 31, 2013			Mar. 25, 2012
Service cost-benefits earned during the period	$	175		$	175
Interest cost on net benefit obligation	1,525			2,050
Amortization of prior service credit	(2,300		)	(4,800		)
Amortization of actuarial loss	500			650
Net periodic postretirement benefit credit	$	(100	)	$	(1,925	)