Summary Of Significant Accounting Policies (Accounting Changes To Consolidated Statements Of Cash Flows) (Details) - USD ($) $ in Thousands	3 Months Ended										12 Months Ended
	Dec. 31, 2018	[1]	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	[1]	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income	$ 6,006		$ 1,259	$ 4,129	$ 3,104	$ 7,503		$ 1,478	$ 19,071	$ 3,060	$ 14,498	$ 31,112	$ 9,692	[2]
Change in net deferred tax assets											(1,719)	4,117	(4,942)
Prepaid and other assets											(2,761)	350	(992)
Net cash provided by operating activities											$ 32,645	23,851	30,188
As Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income												31,010	9,417
Change in net deferred tax assets												4,073	(5,060)
Prepaid and other assets												496	(599)
Net cash provided by operating activities												23,851	30,188
Adjustments [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income												102	275
Change in net deferred tax assets												44	118
Prepaid and other assets												$ (146)	$ (393)

[1] Net income for the 4th quarter of 2017 includes approximately $2.5 million net tax benefit from non-recurring items of tax benefit and expense related to the Tax Cuts and Jobs Act enacted December 2017 and dissolution of a non-operating foreign subsidiary.

[2] Certain prior year balances have been reclassified to conform to the 2017 presentation (see Note 2 - Summary of Significant Accounting Policies - Reclassifications).