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Investments (Unrealized Gains on Investments) (Details) - USD ($) $ in Thousands	12 Months Ended
	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

X

- Definition

Tax effect of unrealized gain (loss) on investments in accumulated other comprehensive income.

+ References

No definition available.

+ Details

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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.

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- Definition

Total change in unrealized gains/losses on investment securities net of tax.

+ References

No definition available.

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- Definition

This item represents the net unrealized gains (losses) on investments in other comprehensive income.

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- Definition

Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

+ References

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