Consolidated Statements of Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Class of Stock [Line Items]
Cash dividends declared per share	$ 2.60	$ 2.40	$ 2.20
Retained Earnings [Member]
Class of Stock [Line Items]
Cash dividends declared per share	$ 2.60	$ 2.40	$ 2.20