Federal Home Loan Bank Advances - Summary of FHLB Advances (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2020	Dec. 31, 2019
Federal Home Loan Bank, Advances [Line Items]
FHLB advances (fixed rates 0.34% to 4.96% and variable rates 0.16% to 0.18%) maturing July 2020 to January 2030	$ 2,006,430	$ 1,800,664
ASC 815 fair value hedge and other basis adjustments	28,584	22,183
Federal Home Loan Bank advances	$ 2,035,014	$ 1,822,847
Minimum \| FHLB Advances
Federal Home Loan Bank, Advances [Line Items]
Fixed rates	0.34%
Variable rates	0.16%
Maximum \| FHLB Advances
Federal Home Loan Bank, Advances [Line Items]
Fixed rates	4.96%
Variable rates	0.18%

Carrying value as of the balance sheet date of ASC 815 fair valued hedge and other basis adjustments on long-term debt.

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Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages.

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-SubTopic 470
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Including both current and noncurrent portions, Federal Home Loan Bank borrowings initially due beyond one year or beyond the normal operating cycle if longer.

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The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a set, unchanging rate.

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