Debt And Lines Of Credit , Narrative - Line of Credit (Details) - USD ($)	1 Months Ended			3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Jun. 30, 2018	Apr. 30, 2017	Mar. 31, 2020	Sep. 30, 2019	Dec. 31, 2019	Feb. 29, 2020	Oct. 31, 2019	May 31, 2019	Dec. 31, 2018	Apr. 25, 2017
Line of Credit Facility [Line Items]
Financial Instruments Subject to Mandatory Redemption, Term		7 years
Lines of credit				$ 582,774,000		$ 183,898,000
Weighted average interest rate				3.60%		4.00%
Debt weighted average to maturity, length				10 years 7 months 6 days		11 years 1 month 6 days
A&R Facility [Member]
Line of Credit Facility [Line Items]
Lines of credit				$ 100,000,000.0
Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Current Borrowing Capacity											$ 750,000,000.0
Line of credit, borrowing capacity											1,100,000,000
Debt Instrument, Maturity Date			May 21, 2023
Line of credit, additional borrowing capacity											350,000,000.0
Letters of credit outstanding, amount	$ 2,600,000				$ 2,600,000					$ 2,800,000
Line of credit - manufactured home floor plan facility [Member]
Line of Credit Facility [Line Items]
Line of credit, borrowing capacity	$ 12,000,000.0				$ 12,000,000.0
Lines of credit				4,000,000.0		$ 3,300,000
Prime Rate [Member] | Line of credit - manufactured home floor plan facility [Member]
Line of Credit Facility [Line Items]
Basis points					10000.00%
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of credit, borrowing capacity											650,000,000.0
Long-term Debt				424,900,000		$ 123,600,000
Lines of credit				$ 582,774,000
Revolving Credit Facility [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Weighted average interest rate				1.80%		2.70%
Debt weighted average to maturity, length				3 years 2 months 12 days		3 years 6 months
Revolving Credit Facility [Member] | Term Loan [Member]
Line of Credit Facility [Line Items]
Lines of credit				$ 54,200,000		$ 57,000,000.0		$ 58,000,000.0
Revolving Credit Facility [Member] | Eurodollar [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of credit variable interest rate	1.20%				1.20%
Term Loan [Member]
Line of Credit Facility [Line Items]
Line of credit, borrowing capacity									$ 100,000,000.0		$ 100,000,000.0
Term Loan [Member] | Eurodollar [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of credit variable interest rate	1.20%				1.20%
Minimum [Member] | Revolving Credit Facility [Member] | Eurodollar [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Interest rate											1.20%
Minimum [Member] | Term Loan [Member]
Line of Credit Facility [Line Items]
Interest rate	1.20%				1.20%
Maximum [Member] | Prime Rate [Member] | Line of credit - manufactured home floor plan facility [Member]
Line of Credit Facility [Line Items]
Interest rate	7.00%				7.00%
Debt Instrument, Interest Rate, Stated Percentage	6.00%				6.00%
Maximum [Member] | Revolving Credit Facility [Member] | Eurodollar [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Interest rate											2.10%
Maximum [Member] | Term Loan [Member]
Line of Credit Facility [Line Items]
Interest rate	2.05%				2.05%
GTSC [Member]
Line of Credit Facility [Line Items]
Line of credit, borrowing capacity	$ 125,000,000.0				$ 125,000,000.0		$ 140,000,000.0
Long-term Debt	$ 56,000,000.0				$ 56,000,000.0	49,400,000
Ownership percentage	40.00%				40.00%					40.00%
GTSC [Member]
Line of Credit Facility [Line Items]
Long-term Debt	$ 139,900,000				$ 139,900,000	$ 123,400,000
GTSC [Member] | London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Basis points	1.65%