Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 17,890	$ 16,956	$ 37,290	$ 33,125
Other comprehensive income:
Unrealized gain (loss) on debt securities, net of tax	4,980	153	10,972	(5,695)
Change in deferred tax valuation allowance	198
Comprehensive income	$ 23,068	$ 17,109	$ 48,262	$ 27,430

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

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