Consolidated Statements of Shareholders Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Increase (Decrease) in Stockholders' Equity
Cash dividends declared per share (in dollars per share)	$ 0.160	$ 0.160	$ 0.145
Treasury stock acquired (shares)	984,342	419,190	1,105,848