CONSOLIDATED STATEMENT OF STOCKHOLDERS' INVESTMENT (PARENTHETICALS) (USD $)	3 Months Ended												12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Statement of Stockholders' Equity [Abstract]
Cash dividends declared per common share	$ 0.32	$ 0.32	$ 0.32	$ 0.32	$ 0.25	$ 0.25	$ 0.25	$ 0.25	$ 0.20	$ 0.2	$ 0.2	$ 0.2	$ 1.28	$ 1	$ 0.8