Selected Quarterly Data (Unaudited)

12 Months Ended

Dec. 31, 2013

Selected Quarterly Data (Unaudited) [Abstract]

Selected Quarterly Data (Unaudited) [Text Block]

19. Selected Quarterly Data (Unaudited)

Millions, Except Per Share Amounts
2013	Mar. 31		Jun. 30		Sep. 30		Dec. 31
Operating revenues	$	5,290	$	5,470	$	5,573	$	5,630
Operating income		1,633		1,878		1,962		1,973
Net income		957		1,106		1,151		1,174
Net income per share:
Basic		2.05		2.38		2.49		2.56
Diluted		2.03		2.37		2.48		2.55
Millions, Except Per Share Amounts
2012	Mar. 31		Jun. 30		Sep. 30		Dec. 31
Operating revenues	$	5,112	$	5,221	$	5,343	$	5,250
Operating income		1,510		1,724		1,786		1,725
Net income		863		1,002		1,042		1,036
Net income per share:
Basic		1.81		2.11		2.21		2.21
Diluted		1.79		2.10		2.19		2.19

Per share net income for the four quarters combined may not equal the per share net income for the year due to rounding.