Business Segments Additional Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2016 USD ($) segment	Mar. 31, 2015 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	4
Maximum annual revenue of small business clients to be served by RBWM	$ 3
Operating Segments [Member] | RBWM [Member]
Segment Reporting Information [Line Items]
Increase to loss before tax		$ 8