Consolidated Statements of Changes in Equity (Parenthetical) - $ / shares	3 Months Ended				12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Stockholders' Equity [Abstract]
Dividends paid (in dollars per share)	$ 0.085	$ 0.085	$ 0.085	$ 0.085	$ 0.34	$ 0.34	$ 0.255