EMPLOYEE BENEFIT PLANS

6 Months Ended

Jun. 30, 2011

EMPLOYEE BENEFIT PLANS [Abstract]

EMPLOYEE BENEFIT PLANS

EMPLOYEE BENEFIT PLANS

The components of net periodic benefit cost related to our defined benefit plans were as follows:

	Pension Plans (a)						Other Postretirement Benefit Plans
	2011			2010			2011		2010
	(Thousands of Dollars)
For the three months ended June 30:
Components of net periodic benefit cost:
Service cost	$	3,121		$	2,846		$	260	$	226
Interest cost	720			558			222		208
Expected return on assets	(904		)	(579		)	—		—
Amortization of prior service credit	(4		)	(4		)	—		—
Amortization of net loss	121			136			18		21
Net periodic benefit cost	$	3,054		$	2,957		$	500	$	455
For the six months ended June 30:
Components of net periodic benefit cost:
Service cost	$	6,212		$	5,692		$	513	$	452
Interest cost	1,440			1,116			444		416
Expected return on assets	(1,808		)	(1,158		)	—		—
Amortization of prior service credit	(8		)	(8		)	—		—
Amortization of net loss	242			272			36		42
Net periodic benefit cost	$	6,078		$	5,914		$	993	$	910

(a) Includes amounts related to the pension plan, the excess pension plan and the supplemental executive retirement plan.