Income Taxes (Tables)

3 Months Ended

12 Months Ended

Mar. 31, 2014

Dec. 31, 2013

Income Taxes [Abstract]

Summary Of Income Tax Expense

	2014	2013
Three months ended March 31	38.7%	41.1%

	Years Ended December 31,
(Thousands of dollars)	2013		2012		2011
Income (loss) from continuing operations before income taxes	$	257,677		150,119		310,813
Income tax expense (benefit)
Federal - Current	$	89,700		64,059		75,946
Federal - Deferred		(4,761)		(17,098)		17,716
State - Current and deferred		16,412		16,744		29,298
Total	$	101,351		63,705		122,960

Schedule Of Reconciliation Of Income Taxes To Statutory Rate

	Years Ended December 31,
(Thousands of dollars)	2013		2012		2011
Income tax expense based on the U.S. statutory tax rate	$	90,187		52,542		108,785
State income taxes, net of federal benefit		10,668		10,884		19,044
Other, net		496		279		(4,869)
Total	$	101,351		63,705		122,960

Summary Of Deferred Tax Assets And Deferred Tax Liabilities

	Years Ended December 31,
(Thousands of dollars)	2013		2012
Deferred tax assets
Property costs	$	6,456		5,729
Asset retirement obligations		5,844		6,187
Other deferred tax assets		9,479		5,507
Total gross deferred tax assets		21,779		17,423
Less valuation allowance		-		-
Net deferred tax assets		21,779		17,423
Deferred tax liabilities
Accumulated depreciation and amortization		(115,737)		(127,182)
Deferred turnaround costs		(84)		(137)
State deferred taxes		(16,423)		(13,789)
Other deferred tax liabilities		(11,610)		(18,911)
Total gross deferred tax liabilities		(143,854)		(160,019)
Net deferred tax liabilities	$	(122,075)		(142,596)