Condensed Consolidated Statements of Stockholders' Equity (Parenthetical) (USD $)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2013	Dec. 31, 2012
Deferred compensation plan held Rabbi Trust (in shares)	34,224	34,224	33,461
Shares issued under the performance incentive plan withheld for employee taxes (in shares)		10,411	5,670
Cash dividends declared per share of common stock (in usd per share)	$ 0.385	$ 1.135	$ 1.440