Condensed Consolidated Statements of Stockholders' Equity (Parenthetical) - shares	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Statement of Stockholders' Equity [Abstract]
Stock issued for benefit plans (shares)	0	352,476
Purchase of treasury stock (shares)	63,211	70,437
Employee stock purchase plan (shares)	0	87,629
Issuance of restricted stock (shares)	223,690	304,166