Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Reclassifications out of accumulated other comprehensive income
Losses on investment securities available-for-sale	$ 0	$ (345)
Income before income taxes	28,950	24,996
Income tax expense	(6,754)	(5,880)
Net income	22,196	19,116
Unrealized gains and losses on available-for-sale securities \| Amount Reclassified from Accumulated Other Comprehensive Income
Reclassifications out of accumulated other comprehensive income
Losses on investment securities available-for-sale	0	(345)
Income before income taxes	0	(345)
Income tax expense	0	83
Net income	$ 0	$ (262)

Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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