Condensed Consolidated Statements of Stockholders' Equity (Parenthetical) - shares	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Statement of Stockholders' Equity [Abstract]
Stock issued for benefit plans (shares)	352,476	154,665
Purchase of treasury stock (shares)	53,319	102,673
Employee stock purchase plan (shares)	87,629	71,825
Issuance of restricted stock (shares)	242,666	392,292