Condensed Consolidated Statements of Shareholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Common equities	Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income	Treasury Stock
Beginning Balance at Dec. 31, 2015		$ 397	$ 1,232	$ 4,762	$ 1,344	$ (1,308)
Share-based awards		0	(10)			18
Share-based compensation			7
Other			1			1
Net Income	$ 188			188
Dividends declared				(79)
Other comprehensive income	187				187
Shares acquired - share repurchase authorization						0
Shares acquired - share-based compensation plans						(5)
Ending Balance at Mar. 31, 2016	6,735	$ 397	1,230	4,871	1,531	(1,294)
Beginning Balance (in shares) at Dec. 31, 2015		163.9
Share-based awards (in shares)		0.5
Shares acquired - share repurchase authorization (in shares)		0.0
Shares acquired - share-based compensation plans (in shares)		0.0
Other (in shares)		0.0
Ending Balance (in shares) at Mar. 31, 2016		164.4
Beginning Balance at Dec. 31, 2016	7,060	$ 397	1,252	5,037	1,693	(1,319)
Share-based awards		0	(18)			17
Share-based compensation			8
Other			1			1
Net Income	201			201
Dividends declared				(82)
Other comprehensive income	87				87
Shares acquired - share repurchase authorization						(15)
Shares acquired - share-based compensation plans						(4)
Ending Balance at Mar. 31, 2017	$ 7,256	$ 397	$ 1,243	$ 5,156	$ 1,780	$ (1,320)
Beginning Balance (in shares) at Dec. 31, 2016	198.3	164.4
Share-based awards (in shares)		0.5
Shares acquired - share repurchase authorization (in shares)		(0.2)
Shares acquired - share-based compensation plans (in shares)		(0.1)
Other (in shares)		0.0
Ending Balance (in shares) at Mar. 31, 2017	198.3	164.6