Divestitures - Schedule of Components of (Loss) Income from Discontinued Operations, Net of Taxes (Detail) - USD ($) $ in Thousands		12 Months Ended
Nov. 17, 2017	Dec. 31, 2018
Discontinued Operations And Disposal Groups [Abstract]
Total noninterest expense		$ 917
Loss from discontinued operations		(917)
Gain on the disposal of discontinued operations	$ 103,600
Total loss from discontinued operations		(917)
Income tax benefit		(170)
Loss from discontinued operations		$ (747)

Amount before tax of income (loss) from a discontinued operation. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal.

Amount of tax expense (benefit) related to a discontinued operation. Includes, but is not limited to, tax expense (benefit) related to income (loss) from operations during the phase-out period, tax expense (benefit) related to gain (loss) on disposal, tax expense (benefit) related to gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and tax expense (benefit) related to adjustments of a prior period gain (loss) on disposal.

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- Definition

Amount after tax of income (loss) from a discontinued operation including the portion attributable to the noncontrolling interest. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal.

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