Industry Segments (Identifiable Assets by Segment) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting, Asset Reconciling Item [Line Items]
Consolidated Assets	$ 21,730,967	$ 21,716,691
Operating Segments | Insurance-Domestic
Segment Reporting, Asset Reconciling Item [Line Items]
Consolidated Assets	16,351,737	16,065,409
Operating Segments | Insurance-International
Segment Reporting, Asset Reconciling Item [Line Items]
Consolidated Assets	1,711,993	1,879,438
Operating Segments | Reinsurance-Global
Segment Reporting, Asset Reconciling Item [Line Items]
Consolidated Assets	2,441,340	2,713,554
Corporate, Other and Eliminations Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Consolidated Assets	$ 1,225,897	$ 1,058,290	[1]

[1] Corporate, other and eliminations represent corporate revenues and expenses and other items that are not allocated to business segments.