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	(9)			29
Share-based compensation			18
Other			3			3
Net Income	$ 491			491
Dividends declared				(237)
Other comprehensive income	408				408
Shares acquired - share repurchase authorization						(2)
Shares acquired - share-based compensation plans						(10)
Ending Balance at Sep. 30, 2016	7,121	$ 397	1,244	5,016	1,752	(1,288)
Beginning Balance (in shares) at Dec. 31, 2015		163.9
Share-based awards (in shares)		0.8
Shares acquired - share repurchase authorization (in shares)		0.0
Shares acquired - share-based compensation plans (in shares)		(0.1)
Stock Issued During Period, Shares, Other		0.1
Ending Balance (in shares) at Sep. 30, 2016		164.7
Beginning Balance at Dec. 31, 2016	7,060	$ 397	1,252	5,037	1,693	(1,319)
Share-based awards		0	(18)			22
Share-based compensation			19
Other			3			3
Net Income	403			403
Dividends declared				(247)
Other comprehensive income	354				354
Shares acquired - share repurchase authorization						(70)
Shares acquired - share-based compensation plans						(6)
Ending Balance at Sep. 30, 2017	$ 7,523	$ 397	$ 1,256	$ 5,193	$ 2,047	$ (1,370)
Beginning Balance (in shares) at Dec. 31, 2016	198.3	164.4
Share-based awards (in shares)		0.7
Shares acquired - share repurchase authorization (in shares)		(1.0)
Shares acquired - share-based compensation plans (in shares)		(0.1)
Stock Issued During Period, Shares, Other		0.0
Ending Balance (in shares) at Sep. 30, 2017	198.3	164.0