CONSOLIDATED STATEMENT OF STOCKHOLDERS' INVESTMENT AND REDEEMABLE NONCONTROLLING INTERESTS (PARENTHETICALS) - $ / shares	3 Months Ended												12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	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, 2016	Mar. 31, 2015	Mar. 31, 2014
Statement of Stockholders' Equity [Abstract]
Cash dividends declared per common share	$ 0.07	$ 0.34	$ 0.34	$ 0.34	$ 0.32	$ 0.32	$ 0.32	$ 0.32	$ 0.25	$ 0.25	$ 0.25	$ 0.25	$ 1.09	$ 1.28	$ 1.00