Employee Benefits (Tables)

3 Months Ended

Mar. 30, 2013

Employee Benefits

Schedule of net periodic benefits cost of plans

	Three Months Ended
	March 30,	March 31,
(Thousands of dollars)	2013	2012
Components of net periodic benefit cost:
Service cost	$   2,421	$   2,226
Interest cost	2,068	2,258
Expected return on plan assets	(1,612)	(1,592)
Amortization and other	1,636	1,530
Net periodic benefit cost	$   4,513	$   4,422