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Investments (Unrealized Gains on Investments) (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Net unrealized gains | $ 2,391 | $ 124,679 | $ 64,804
Deferred income tax expense | (502) | (44,103) | (22,681)
Net unrealized gains, net of deferred income tax | 1,889 | 80,576 | 42,123
Increase (decrease) in net unrealized gains in OCI, net of deferred income tax | (65,881) | 38,453 | (2,873)
AFS Fixed Income Securities [Member] |  |  |
Net unrealized gains | 2,302 | 85,806 | 38,781
Equity Securities [Member] |  |  |
Net unrealized gains | 0 | 38,894 | 25,864
Available-for-sale Securities [Member] |  |  |
Net unrealized gains | 2,302 | 124,700 | 64,645
Total HTM Securities [Member] |  |  |
Net unrealized gains | 89 | (21) | 159
Accounting Standards Update 2018-02 [Member] | Investments [Member] |  |  |
Cumulative effect adjustment | (17,920) | 0 | 0
Accounting Standards Update 2018-02 [Member] | Retained Earnings [Member] |  |  |
Cumulative effect adjustment | 5,707 | 0 | 0
Accounting Standards Update 2016-01 [Member] |  |  |
Cumulative effect adjustment | 30,726 | 0 | 0
Accounting Standards Update 2016-01 [Member] | Retained Earnings [Member] |  |  |
Cumulative effect adjustment | $ (30,726) | $ 0 | $ 0

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- Definition This item represents the net unrealized gains (losses) on investments in other comprehensive income, net of deferred income tax. + References No definition available. + Details
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