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Statements of Cash Flow (Cash Flow Supplemental Disclosures) (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015
Interest		$ 13,874	$ 13,843
Federal income tax		36,405	18,500
Corporate actions related to equity securities, AFS	[1]	3,032	4,239
Assets acquired under capital lease arrangements		3,108	6,933
Non-cash purchase of property and equipment		648	0
AFS Fixed Maturity Securities [Member]
Exchange of fixed income securities		21,775	35,425
Held-to-maturity Securities [Member]
Exchange of fixed income securities		0	10,045
National Flood Insurance Program [Member]
Restricted cash		$ 20,900	$ 9,900
[1] Examples of such corporate actions include non-cash acquisitions and stock splits.

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- Definition

The increase during the period in capital lease obligations due to entering into new capital leases.

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