Condensed Consolidated Statements of Changes in Equity (Parenthetical) - $ / shares	3 Months Ended					9 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	Jun. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Stockholders' Equity [Abstract]
Cash dividends declared per share (in $ per share)	$ 0.45	$ 0.45	$ 0.45	$ 0.45	$ 0.45	$ 1.35	$ 0.90