Significant Accounting Policies - Financing Receivables (Details) - Total Lease Receivable and Loan Receivable Portfolio Segments	12 Months Ended
Dec. 31, 2019 item segment
Financing receivables
Number of portfolio segments \| segment	2
Number of classes of financing receivable \| item	3
Period after which financing receivables become past due	90 days

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration