Employee and Retiree Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2012

Amounts Included in Accumulated Other Comprehensive Income Not Recognized in Net Periodic Benefit Expense

At December 31, 2012, amounts included in accumulated other comprehensive income (AOCI), before reduction for associated deferred income taxes, which have not been recognized in net periodic benefit expense are shown in the following table.

(Thousands of dollars)	Pension Benefits			Other Postretirement Benefits
Net actuarial loss	$	(238,684	)		(38,706	)
Prior service (cost) credit		(3,987	)		957
Transitional asset (liability)		1,062			(8	)
	$	(241,609	)		(37,757	)

Amounts Included in Accumulated Other Comprehensive Income Expected to be Amortization into Net Periodic Benefit Expense

Amounts included in AOCI at December 31, 2012 that are expected to be amortized into net periodic benefit expense during 2013 are shown in the following table.

(Thousands of dollars)	Pension Benefits			Other Postretirement Benefits
Net actuarial loss	$	(18,800	)		(1,876	)
Prior service (cost) credit		(1,195	)		173
Transitional asset (liability)		529			(8	)
	$	(19,466	)		(1,711	)

Projected Benefit Obligations, Accumulated Benefit Obligations and Fair Value of Plan Assets for Plans where Accumulated Benefit Obligation Exceeded Fair Value of Plan Assets

The table that follows includes projected benefit obligations, accumulated benefit obligations and fair value of plan assets for plans where the accumulated benefit obligation exceeded the fair value of plan assets.

	Projected Benefit Obligations				Accumulated Benefit Obligations				Fair Value of Plan  Assets
(Thousands of dollars)	2012		2011		2012		2011		2012		2011
Funded qualified plans where accumulated benefit obligation exceeds fair value of plan assets	$	587,318		513,444		523,773		459,556		431,788		374,360
Unfunded nonqualified and directors’ plans where accumulated benefit obligation exceeds fair value of plan assets		112,135		96,754		98,498		82,642		0		0
Unfunded other postretirement plans		124,134		114,962		124,134		114,962		0		0

Components of Net Periodic Benefit Expense

The table that follows provides the components of net periodic benefit expense for each of the three years ended December 31, 2012.

	Pension Benefits									Other Postretirement Benefits
(Thousands of dollars)	2012			2011			2010			2012			2011			2010
Service cost	$	23,500			22,406			20,706			3,958			4,547			4,133
Interest cost		29,869			30,785			30,144			5,174			6,141			6,211
Expected return on plan assets		(25,826	)		(25,919	)		(24,199	)		0			0			0
Amortization of prior service cost (credit)		1,254			1,314			1,558			(173	)		(240	)		(263	)
Amortization of transitional (asset) liability		(529	)		(536	)		(514	)		8			8			8
Recognized actuarial loss		16,389			12,484			12,257			1,317			2,329			2,790
		44,657			40,534			39,952			10,284			12,785			12,879
Termination benefits expense		6,177			695			0			0			0			0
Curtailment expense		0			1,036			0			0			(605	)		0
Net periodic benefit expense	$	50,834			42,265			39,952			10,284			12,180			12,879

Weighted-Average Assumptions used in Measurement of Benefit Obligations and Net Periodic Benefit Expense

The following table provides the weighted-average assumptions used in the measurement of the Company’s benefit obligations at December 31, 2012 and 2011 and net periodic benefit expense for 2012 and 2011.

	Benefit Obligations												Net Periodic Benefit Expense
	Pension Benefits						Other Postretirement Benefits						Pension Benefits						Other Postretirement Benefits
	December 31						December 31						Year						Year
	2012			2011			2012			2011			2012			2011			2012			2011
Discount rate		4.24	%		5.00	%		4.18	%		4.87	%		4.80	%		5.50	%		4.87	%		5.50	%
Expected return on plan assets		6.20	%		6.48	%		0	%		0	%		6.20	%		6.48	%		0	%		0	%
Rate of compensation increase		4.13	%		4.22	%		0	%		0	%		4.10	%		4.22	%		0	%		0	%

Benefit Payments Reflecting Expected Future Service as Appropriate which are Expected to be Paid in Future Years from Assets of Plans or by Company

Benefit payments, reflecting expected future service as appropriate, which are expected to be paid in future years from the assets of the plans or by the Company are shown in the following table.

(Thousands of dollars)	Pension Benefits		Other Postretirement Benefits
2013	$	31,968		7,231
2014		32,978		7,512
2015		33,770		7,778
2016		34,461		8,074
2017		35,627		8,379
2018-2022		202,836		47,829

One Percent Change in Assumed Health Care Cost Trend Rates

A 1% change in assumed health care cost trend rates would have the following effects.

(Thousands of dollars)	1% Increase		1% Decrease
Effect on total service and interest cost components of net periodic postretirement benefit expense for the year ended December 31, 2012	$	1,777		(1,383	)
Effect on the health care component of the accumulated postretirement benefit obligation at December 31, 2012		19,599		(15,724	)

Funded Defined Benefit Pension Plans

Asset Allocation for Benefit Plans

The weighted average asset allocation for the Company’s funded pension benefit plans at December 31, 2012 and 2011 are presented in the following table.

	December 31,
	2012			2011
Equity securities		62.9	%		62.3	%
Fixed income securities		36.1			36.5
Cash equivalents		1.0			1.2
		100.0	%		100.0	%

Foreign Plans

Plans' Benefit Obligations and Fair Value of Assets and Statement of Funded Status

The preceding tables in this note include the following amounts related to foreign benefit plans.

	Pension Benefits				Other Postretirement Benefits
(Thousands of dollars)	2012		2011		2012		2011
Benefit obligation at December 31	$	184,550		153,947		525		454
Fair value of plan assets at December 31		164,111		135,608		0		0
Net plan liabilities recognized		20,439		18,339		525		454
Net periodic benefit expense		11,022		8,978		88		82

Domestic Plans

Plans' Benefit Obligations and Fair Value of Assets and Statement of Funded Status

The tables that follow provide a reconciliation of the changes in the plans’ benefit obligations and fair value of assets for the years ended December 31, 2012 and 2011 and a statement of the funded status as of December 31, 2012 and 2011.

	Pension Benefits						Other Postretirement Benefits
(Thousands of dollars)	2012			2011			2012			2011
Change in benefit obligation
Obligation at January 1	$	629,568			575,300			114,962			122,879
Service cost		23,500			22,406			3,958			4,547
Interest cost		29,869			30,785			5,174			6,141
Plan amendments		0			483			0			0
Participant contributions		30			35			1,035			1,049
Actuarial loss		55,479			66,010			4,686			4,791
Medicare Part D subsidy		0			0			432			555
Exchange rate changes		7,125			(2,109	)		14			(11	)
Benefits paid		(30,217	)		(27,745	)		(6,127	)		(5,667	)
Reduction due to sale of the Superior refinery		0			(23,021	)		0			0
Special termination benefits		6,177			695			0			0
Curtailments		0			(13,271	)		0			(19,322	)
Obligation at December 31		721,531			629,568			124,134			114,962
Change in plan assets
Fair value of plan assets at January 1		404,350			416,272			0			0
Actual return on plan assets		41,674			(1,415	)		0			0
Employer contributions		42,207			38,357			4,660			4,063
Participant contributions		30			35			1,035			1,049
Medicare Part D subsidy		0			0			432			555
Exchange rate changes		6,289			(1,786	)		0			0
Benefits paid		(30,217	)		(27,745	)		(6,127	)		(5,667	)
Distribution to acquirer of the Superior refinery		0			(18,720	)		0			0
Other		(787	)		(648	)		0			0
Fair value of plan assets at December 31		463,546			404,350			0			0
Funded status and amounts recognized in the Consolidated Balance Sheets at December 31
Deferred charges and other assets		9,679			10,621			0			0
Other accrued liabilities		(5,556	)		(3,488	)		(5,646	)		(5,022	)
Deferred credits and other liabilities		(262,108	)		(232,351	)		(118,488	)		(109,940	)
Funded status and net plan liability recognized at December 31	$	(257,985	)		(225,218	)		(124,134	)		(114,962	)

Other Postretirement Benefits

Asset Allocation for Benefit Plans

At December 31, 2012 and 2011, the fair value measurements of retirement plan assets within the fair value hierarchy are included in the table that follows.

			Fair Value Measurements Using
(Thousands of dollars)	Fair Value at December 31, 2012		Quoted Prices in Active  Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Domestic Plans
Equity securities:
U.S. core equity	$	83,392		83,392		0		0
U.S. small/midcap		20,894		20,894		0		0
U.S. long/short equity fund		14,654		0		14,654		0
International commingled trust fund		62,111		0		62,111		0
Emerging market commingled equity fund		9,535		0		9,535		0
Fixed income securities:
U.S. fixed income		80,203		0		80,203		0
International commingled trust fund		15,179		0		15,179		0
Emerging market mutual fund		10,060		0		10,060		0
Cash and equivalents		3,407		3,407		0		0
Total Domestic Plans		299,435		107,693		191,742		0
Foreign Plans
Equity securities funds		79,233		0		79,233		0
Fixed income securities funds		51,777		0		51,777		0
Diversified pooled fund		31,758		0		31,758		0
Cash and equivalents		1,343		1,343		0		0
Total Foreign Plans		164,111		1,343		162,768		0
Total	$	463,546		109,036		354,510		0
			Fair Value Measurements Using
(Thousands of dollars)	Fair Value at December 31, 2011		Quoted Prices in Active  Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Domestic Plans
Equity securities:
U.S. core equity	$	73,986		73,986		0		0
U.S. small/midcap		18,236		18,236		0		0
U.S. long/short equity fund		13,860		0		13,860		0
International commingled trust fund		56,156		0		56,156		0
Emerging market commingled equity fund		6,980		0		6,980		0
Fixed income securities:
U.S. fixed income		76,764		0		76,764		0
International commingled trust fund		13,109		0		13,109		0
Emerging market mutual fund		6,448		0		6,448		0
Cash and equivalents		3,203		3,203		0		0
Total Domestic Plans		268,742		95,425		173,317		0
Foreign Plans
Equity securities funds		59,349		0		59,349		0
Fixed income securities funds		44,442		0		44,442		0
Diversified pooled fund		29,990		0		29,990		0
Cash and equivalents		1,827		1,827		0		0
Total Foreign Plans		135,608		1,827		133,781		0
Total	$	404,350		97,252		307,098		0