Condensed Consolidated Statements of Stockholders' Equity (Parenthetical) (USD $)	3 Months Ended	9 Months Ended
	Dec. 31, 2013	Sep. 30, 2014	Sep. 30, 2013
Statement of Stockholders' Equity [Abstract]
Cash dividends declared on common stock, per share (in dollars per share)	$ 0.125	$ 0.405	$ 0.250
Common stock issued per share for stock bonus (in dollars per share)	$ 0	$ 35.87	$ 33.81