Consolidated Statements of Stockholders' Equity (Parenthetical) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Statement of Stockholders' Equity [Abstract]
Shares issued from stock option exercises	29,199	0
Purchase of treasury shares (shares)	15,107	28,279
Issuance of common stock (shares)	0	1,403,508
Issuance of restricted stock (shares)	107,388	141,818