Share-Based Compensation - Option Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based Compensation Expense	$ 4,861	$ 3,724	$ 4,190
Current Year Stock Option Awards [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based Compensation Expense	665	0	0
Unrecognized Compensation Expense, Options	1,000
Prior Year Stock Option Awards [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based Compensation Expense	364	310	0
Unrecognized Compensation Expense, Options	400
Second Prior Year Stock Option Awards [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based Compensation Expense	369	367	308
Unrecognized Compensation Expense, Options	100
Third Prior Year Stock Option Awards [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based Compensation Expense	$ 50	$ 332	$ 332