Deposits - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Banking and Thrift, Other Disclosures [Abstract]
Deposits	$ 22,803,143		$ 22,666,039
Brokered deposits	12,100,000		11,900,000
Retail and other deposits	10,700,000		10,800,000
Stable interest-bearing deposits, total	7,900,000		7,100,000
Brokered deposit placement fee	4,000	$ 5,000
Third party broker fees paid	0	$ 2,000
Deposits exceeding FDIC insurance limits	751,000		571,000
Accrued interest on deposits	$ 61,000		$ 50,000

Carrying value as of the balance sheet date of [accrued] interest payable on all forms of debt, including trade payables, that has been incurred and is unpaid. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=121566466&loc=d3e7018-107765

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=121566466&loc=d3e6935-107765

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.20)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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