Share-Based Compensation Plans - Share options activity (Details) - Share options [Member] - $ / shares shares in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Share Options (in shares)
Beginning outstanding	2,300	3,462
Granted	0	0
Exercised	(1,432)	(953)
Forfeited and expired	(13)	(6)
Outstanding at end of period	855	2,503
Exercisable at end of period	855	2,464
Weighted-Average Exercise Price (in dollars per share)
Beginning outstanding	$ 32	$ 32
Granted	0	0
Exercised	27	32
Forfeited and expired	39	37
Outstanding at end of period	40	32
Exercisable at end of period	$ 40	$ 32