New Accounting Principles and Recent Accounting Pronouncements (Tables)

12 Months Ended

Dec. 31, 2015

New Accounting Principles and Recent Accounting Pronouncements [Abstract]

Summary Of Adjustments From Change In Accounting Principle

	As Previously
	Reported		Adjustment	December 31, 2014
(Thousands of dollars)	December 31, 2014		Effect	As Adjusted
Deferred charges and other assets	$	81,151	(18,569)	62,582
Long-term debt		(2,536,238)	18,569	(2,517,669)