Share-Based Compensation Plans Restricted share unit activity (Details) (Restricted share units (RSUs) [Member], USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Restricted share units (RSUs) [Member]
Non-vested share awards (in shares)
Non-vested at beginning of period	8,381		9,759
Granted	957		1,146
Vested	(1,714)		(1,950)
Forfeited	(49)		(125)
Non-vested at end of period	7,575		8,830
Weighted Average Fair value (in dollars per share)
Non-vested at beginning of period	$ 63	[1]	$ 51	[1]
Granted	$ 97	[1]	$ 83	[1]
Vested	$ 59	[1]	$ 51	[1]
Forfeited	$ 64	[1]	$ 50	[1]
Non-vested at end of period	$ 69	[1]	$ 56	[1]

[1] Represents per share weighted average fair value of award at date of grant.