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Statements of Cash Flow (Cash Flow Supplemental Disclosures) (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Interest | $ 23,992 | $ 23,905 | $ 22,098
Federal income tax | 29,193 | 62,000 | 46,405
Corporate actions related to equity securities | 944 | 4,725 | 3,263
Assets acquired under capital lease arrangements | 4,119 | 278 | 3,151
Non-cash purchase of property and equipment | 291 | 0 | 78
AFS Fixed Income Securities [Member] |  |  |
Corporate actions related to fixed income securities, AFS | $ 52,277 | $ 22,511 | $ 23,579

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