Retirement Plans (Tables)

12 Months Ended

Dec. 31, 2014

Retirement Plans [Abstract]

Schedule of Expected Benefit Payments [Table Text Block]

Benefit payments during the next ten years, which reflect applicable future service, are as follows:

Year Ended December 31,	Amount
(Thousands of dollars)
2015	$	1,538
2016	$	1,524
2017	$	1,210
2018	$	1,429
2019	$	1,403
Years 2020 to 2024	$	7,311

Periodic Pension Cost, Next Fiscal Year [Table Text Block]

The following is an estimate of the components of net periodic pension cost in 2015:

Estimated Year Ended December 31,	2015
(Thousands of dollars)
Service cost	$	44
Interest cost	1,230
Amortization of actuarial loss	535
Estimated 2015 net periodic pension cost	$	1,809

Schedule of Changes in Projected Benefit Obligations [Table Text Block]

The following table summarizes the changes in plan benefit obligations:

Year Ended December 31,	2014			2013
(Thousands of dollars)
Change in benefit obligation
Beginning benefit obligation	$	25,145		$	29,075
Service cost	84			230
Interest cost	1,171			1,159
Actuarial loss (gain)	5,014			(3,526		)
Curtailment	—			(521		)
Benefit payments	(1,367		)	(1,272		)
Ending benefit obligation	$	30,047		$	25,145

Schedule of Defined Benefit Plans Disclosures [Table Text Block]

Year Ended December 31,	2014			2013
(Thousands of dollars)
Change in plan assets
Fair value of plan assets at beginning of year	$	—		$	—
Employer contribution	1,367			1,272
Benefit payments	(1,367		)	(1,272		)
Fair value of plan assets at end of year	$	—		$	—
Funded Status	$	(30,047	)	$	(25,145	)
Amounts recognized in the consolidated balance sheets consist of:
Accrued liabilities	$	(1,507	)	$	(1,461	)
Other non-current liabilities	(28,540		)	(23,684		)
Net amount recognized	$	(30,047	)	$	(25,145	)
Amounts recognized in accumulated other comprehensive loss consist of:
Net actuarial loss	$	8,399		$	3,713
Prior service cost	(1		)	(1		)
Net amount recognized, before tax effect	$	8,398		$	3,712
Weighted average assumptions used to determine benefit obligations:
Discount rate	4.2		%	4.8		%
Rate of compensation increase	3.0		%	3.0		%

Schedule of Net Benefit Costs [Table Text Block]

Components of net periodic pension cost are described in the following table:

Year Ended December 31,	2014			2013			2012
(Thousands of dollars)
Components of net periodic pension cost:
Service cost	$	84		$	230		$	249
Interest cost	1,171			1,159			1,242
Amortization of actuarial loss	328			430			268
Net periodic pension cost	$	1,583		$	1,819		$	1,759
Weighted average assumptions used to determine net periodic pension cost:
Discount rate	4.8		%	4.0		%	5.0		%
Rate of compensation increase	3.0		%	3.0		%	3.0		%