Stock-Based Compensation Plans Market Stock Units (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
MSU Expense	$ 1,200,000	$ 900,000
Number of Market Stock Units
Outstanding on December 31, 2017	221,936
Granted	32,194
Exchanged for stock (1)	(60,995)
Outstanding on December 31, 2018	193,135	221,936
Maximum Shares Potentially Issuable
Outstanding on December 31, 2017	332,904
Granted	48,292
Exchanged for stock (1)	(46,799)
Outstanding on December 31, 2018	279,542	332,904
Common shares issued in exchanged for MSUs	46,799
MSU Shares Maximum vs Earned	0
MSU Potential Common Shares Issuable Change	(54,855)
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Potential Shares From MSU Vest	$ 0
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Potential Shares From MSU Vest	$ 1.50
Trading days	60 days