Employee and Retiree Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2012

Components of Net Periodic Benefit Expense

The table that follows provides the components of net periodic benefit expense for the three-month and nine-month periods ended September 30, 2012 and 2011.

	Three Months Ended September 30,
	Pension Benefits						Other Postretirement Benefits
(Thousands of dollars)	2012			2011			2012			2011
Service cost	$	6,030			5,915			1,049			1,289
Interest cost		7,549			7,919			1,342			1,719
Expected return on plan assets		(6,520	)		(6,840	)		0			0
Amortization of prior service cost		313			337			(42	)		(66	)
Amortization of transitional asset		112			(51	)		2			3
Recognized actuarial loss		3,846			2,543			453			786
		11,330			9,823			2,804			3,731
Special termination benefits		0			700			0			0
Curtailment expense (gain)		0			1,105			0			(605	)
Net periodic benefit expense	$	11,330			11,628			2,804			3,126

	Nine Months Ended September 30,
	Pension Benefits						Other Postretirement Benefits
(Thousands of dollars)	2012			2011			2012			2011
Service cost	$	17,953			17,763			3,139			3,803
Interest cost		22,386			23,855			4,133			5,084
Expected return on plan assets		(19,345	)		(20,634	)		0			0
Amortization of prior service cost		938			1,020			(131	)		(196	)
Amortization of transitional asset		339			(155	)		6			7
Recognized actuarial loss		11,460			7,661			1,394			2,326
		33,731			29,510			8,541			11,024
Special termination benefits		6,170			700			0			0
Curtailment expense (gain)		0			1,105			0			(605	)
Net periodic benefit expense	$	39,901			31,315			8,541			10,419