Common and Preferred Stock (Tables)

12 Months Ended

Dec. 31, 2016

Text Block [Abstract]

Schedule of Share Repurchases

In millions, except per share amounts		2016		2015		2014
Number of shares repurchased		16.6		39.9		3.3
Average price paid per share	$	6.37	$	7.60	$	10.45
Remaining authorization as of December 31	$	88	$	94	$	188