Customer Notes Receivable - Fair Value of Customer Notes Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Carrying Value
Accounts, Notes, Loans and Financing Receivable [Line Items]
Customer notes receivable	$ 311,732	$ 179,632
Estimated Fair Value
Accounts, Notes, Loans and Financing Receivable [Line Items]
Customer notes receivable	$ 314,222	$ 179,990

Fair value portion of an agreement for an unconditional promise by the maker to pay the holder a definite sum of money at a future date.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.3(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_NotesReceivableFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant