Notes Receivable - Interest Income and Payments Received (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest income	$ 2,908	$ 2,753
Notes Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest income	2,600	2,700
Payment received relating to notes receivables	$ 3,000	$ 3,100

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.

+ Details

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Period Type:	duration

- Definition

Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.7(b))
-URI http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599

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- Definition

The cash inflow associated with principal collections from a borrowing supported by a written promise to pay an obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3179-108585

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Balance Type:	debit
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