Loans Receivable - Lending Commitments (Details) - Investment Commitments - Consolidated Real Estate Debt Investments $ in Millions	Sep. 30, 2020 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other commitments	$ 133.6
Parent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other commitments	$ 29.5

Minimum amount of other commitment not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in the taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions.

No definition available.

Name:	us-gaap_OtherCommitment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant