CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 201,608	$ 66,956	$ 93,229
Other comprehensive (loss) income:
Unrealized (loss) gain on debt securities on which an other-than-temporary impairment has been recognized	255	(896)	550
Reclassification adjustment for OTTI on debt securities included in net income	50	12,231	6,687
Reduction of non-credit OTTI component on securities sold	0	5,678	0
Reclassification adjusment for net gain included in net income on debt securities sold on which an OTTI has been recognized	0	(371)	0
Reclassification adjustments for net loss (gain) included in net income on other sales of available-for-sale securities	34	0	(6,104)
All other unrealized holding losses on available-for-sale securities arising during the year	(20,145)	(2,867)	(7,774)
Other comprehensive (loss) income for the year	(19,806)	13,775	(6,641)
Total comprehensive income	$ 181,802	$ 80,731	$ 86,588

Other than temporary impairment losses subsequent unrealized gain on debt securities.

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This item represents reductions in the cumulative amount of noncredit losses recognized in accumulated other comprehensive income because of the sale of other than temporarily impaired securities.

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Recovery of previously recorded other than temporary impairment charges on debt securities sold during the period.

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Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Amount before tax of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities.

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Amount before tax and reclassification adjustments of unrealized holding gain (loss) on available-for-sale securities.

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The amount of other than temporary impairment losses on investments in debt and equity securities categorized as Available-for-sale which have been recognized in earnings during the period. Such impairment losses consist of other than temporary impairments (OTTI) on equity securities, credit losses on investments in debt securities, and when the entity intends to sell an impaired debt security or it is more likely than not that the entity will be required to sell the impaired debt security before recovery of its amortized cost basis.

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