Accrued and Other Current Liabilities (Tables)

12 Months Ended

Dec. 31, 2014

Payables and Accruals [Abstract]

Schedule of Accrued Liabilities

Accrued and other current liabilities as of December 31 consisted of the following:

	2014		2013
	(Thousands of dollars)
Salaries & wages	$	16,203	$	14,318
Incentive compensation		11,730		11,617
Income taxes		3,787		6,790
Interest		7,891		5,621
Vacation payable		6,112		5,751
Group medical		1,735		1,516
Transportations tax		907		1,975
Operating lease		1,227		1,048
Workers compensation		1,185		3,684
Other		2,035		2,211
Total accrued liabilities	$	52,812	$	54,531