Variable Interest Entities - Summary (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Variable Interest Entity [Line Items]
Investment securities available-for-sale	$ 2,679,070	$ 4,273,864
Accrued expenses and other liabilities	223,201	203,962
Other assets	258,522	260,204
Assets	21,993,919	21,094,429
Liabilities	19,238,700	18,208,118
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Maximum Loss	180,099	200,769
Assets	145,964	167,097
Liabilities	17,104	17,567
Variable Interest Entity, Not Primary Beneficiary | Multifamily Loan Securitization
Variable Interest Entity [Line Items]
Investment securities available-for-sale	66,496	81,103
Accrued expenses and other liabilities	338	338
Variable Interest Entity, Not Primary Beneficiary | Multifamily Loan Securitization, Asset
Variable Interest Entity [Line Items]
Maximum Loss	66,496	81,103
Variable Interest Entity, Not Primary Beneficiary | Multifamily Loan Securitization, Liability
Variable Interest Entity [Line Items]
Maximum Loss	50,901	50,901
Variable Interest Entity, Not Primary Beneficiary | Affordable Housing Partnership
Variable Interest Entity [Line Items]
Accrued expenses and other liabilities	16,766	17,229
Other assets	79,468	85,994
Variable Interest Entity, Not Primary Beneficiary | Affordable Housing Partnership, Asset
Variable Interest Entity [Line Items]
Maximum Loss	62,702	68,765
Variable Interest Entity, Not Primary Beneficiary | Affordable Housing Partnership, Liability
Variable Interest Entity [Line Items]
Maximum Loss	$ 0	$ 0