Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 32
-Paragraph 2A
-URI http://asc.fasb.org/extlink&oid=82859839&loc=SL82860478-203043

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130543-203045

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130539-203045

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130545-203045

Name:	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Segment Information - Narrative (Details) $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended		51 Months Ended
Segment Information - Narrative (Details) $ in Millions	Jun. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) segment	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($)
Segments
Number of reportable operating segments \| segment				4
Percentage of resort fees included in revenue	50.00%	50.00%		50.00%		50.00%
Mattamy - RiverTown sale
Segments
Impact fees received	$ 23.1	$ 23.3	$ 0.2	$ 23.5	$ 0.3	$ 25.1
Real estate - Impact fees \| Mattamy - RiverTown sale
Segments
Impact fees received	$ 23.1
Real estate - Impact fees \| Residential real estate \| Mattamy - RiverTown sale
Segments
Revenue		23.1		23.1
Mitigation bank credit \| Corporate/Other
Segments
Revenue		$ 2.2		$ 2.2