Leases - Narrative (Details) $ in Thousands	May 18, 2023 USD ($) ft² $ / ft²	Jun. 30, 2023 USD ($) ft² property	May 01, 2023 ft²	Mar. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Operating Leases [Line Items]
Area of real estate property (in square feet) | ft²		9,400,000
Number of properties subject to ground leases | property		3
Right-of-use assets		$ 28,554			$ 28,670
Lease liabilities		$ 28,554			$ 28,670
Weighted average discount rate (as a percent)		4.50%
Weighted average remaining lease term (in years)		46 years 10 months 24 days
Signature Bridge Bank | Building
Operating Leases [Line Items]
Straight-line rent reserve				$ (6,400)
Flagstar Bank, N.A | Building
Operating Leases [Line Items]
Straight-line rent reserve	$ 5,800
Area of real estate property (in square feet) | ft²	313,109
Reduction rate | $ / ft²	3
Lessor, Operating Lease, Term Of Rate Reduction	5 years
First Republic Bank | Building
Operating Leases [Line Items]
Straight-line rent reserve		$ 200
Area of real estate property (in square feet) | ft²			14,430
Minimum
Operating Leases [Line Items]
Term of lease (in years)		1 year
Maximum
Operating Leases [Line Items]
Term of lease (in years)		22 years