Unaudited Quarterly Data

12 Months Ended

Dec. 31, 2020

Quarterly Financial Data [Abstract]

Unaudited Quarterly Data

Note 22: Unaudited Quarterly Data

Presented in the tables below are supplemental, unaudited, consolidated, quarterly financial data for each of the four quarters in the years ended December 31, 2020 and 2019, respectively. The operating results for any quarter are not indicative of results that may be expected for a full year or any future periods.

	2020
	First Quarter		Second Quarter		Third Quarter		Fourth Quarter
Operating revenues	$	844	$	931	$	1,079	$	923
Operating income	239		313		433		263
Net income attributable to common shareholders	124		176		264		145
Basic earnings per share: (a)
Net income attributable to common shareholders	$	0.69	$	0.97	$	1.46	$	0.80
Diluted earnings per share:
Net income attributable to common shareholders	0.68		0.97		1.46		0.80

(a)Amounts may not sum due to rounding.

	2019
	First Quarter		Second Quarter		Third Quarter		Fourth Quarter
Operating revenues	$	813	$	882	$	1,013	$	902
Operating income	238		302		406		224
Net income attributable to common shareholders	113		170		240		98
Basic earnings per share: (a)
Net income attributable to common shareholders	$	0.62	$	0.94	$	1.33	$	0.54
Diluted earnings per share:
Net income attributable to common shareholders	0.62		0.94		1.33		0.54

(a)Amounts may not sum due to rounding.