Segment Information (Schedule of Reconciliation of Total Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
ASSETS
Segment Assets	$ 2,693,802	$ 2,760,727	$ 2,707,099
Items excluded from segment assets:
Deferred Tax Assets	319,839	280,055
Operating Segments | Segment Assets for Total Reportable Business Segments
ASSETS
Segment Assets	1,981,721	1,894,209
Operating Segments | Segment Assets for All Other Business Segments
ASSETS
Segment Assets	515,334	554,315
Corporate Reconciling Items And Eliminations
Items excluded from segment assets:
Cash and Other Investments	93,242	234,658
Deferred Tax Assets	$ 103,505	$ 77,545