Summarized Quarterly Financial Data (Unaudited)

12 Months Ended

Dec. 31, 2013

Quarterly Financial Information Disclosure [Abstract]

Summarized Quarterly Financial Data (Unaudited)



	Quarter Ended
(Thousands of Dollars)	March 31, 2013		June 30, 2013		Sept. 30, 2013		Dec. 31, 2013
Operating revenues	$	1,117,457	$	966,429	$	1,044,300	$	1,074,442
Operating income	212,299		183,675		289,741		143,044
Net income	116,605		97,299		166,266		73,213



	Quarter Ended
(Thousands of Dollars)	March 31, 2012		June 30, 2012		Sept. 30, 2012		Dec. 31, 2012
Operating revenues	$	1,076,052	$	869,501	$	992,287	$	1,031,453
Operating income	188,906		192,310		315,391		152,612
Net income	93,285		95,407		192,443		76,941

- Definition

The entire disclosure for the quarterly financial data in the annual financial statements. The disclosure may include a tabular presentation of financial information for each fiscal quarter for the current and previous year, including revenues, gross profit, income or loss before extraordinary items and earnings per share data. It also includes an indication if the information in the note is unaudited, comments on the aggregate effect of year-end adjustments, and an explanation of matters or transactions that affect comparability or are pertinent to an understanding of the information furnished.

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