Consolidated Statements of Shareholders' Equity (Parenthetical)	12 Months Ended
	Dec. 31, 2017 $ / shares shares	Dec. 31, 2016 $ / shares shares	Dec. 31, 2015 $ / shares shares
Cash dividends paid on common shares, per share | $ / shares	$ 0.44	$ 0.4100	$ 0.26
Issuance under equity compensation plans, shares	174,895	213,234	179,600
Stock Issued During Period, Shares, Conversion of Convertible Securities	0	0	0
Total shares awarded to JCB shareholders		0	0