Consolidated Statements Of Stockholders' Equity (Parentheticals) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Stockholders' Equity [Abstract]
Purchase of common shares for treasury (shares)	0	5,000	80,512
Common shares issued, net shares withheld for taxes	27,951	96,916	59,113