Common Stock (Schedule of Restricted Stock Tax Expense and Deferred Tax) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Capitalized costs related to restricted stock award expense		$ 300	$ 300	$ 300
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense	[1]	3,198	2,997	2,594
Deferred tax benefit		671	1,049	908
Current tax benefit recognized		$ 117	$ 318	$ 183

[1] Any capitalized costs related to these expenses is less than $0.3 million for all years.