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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Part 4 (Details) - USD ($)					12 Months Ended
	May 02, 2018	Jun. 28, 2017	May 03, 2017	May 04, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 09, 2015
Stock Compensation Plans [Abstract]
Granted (in shares)					0	0	0
Unrecognized expense related to non-vested awards of restricted shares granted					$ 64,000
Granted, restricted stock awards (in shares)				5,000
Fair market value (in dollars per share)				$ 27.70
Award vesting period				1 year
Accounts Receivable [Abstract]
Expense related to allowance for doubtful accounts					100,000	$ 200,000
Summary of changes in entity's accounts receivable [Abstract]
Gross accounts receivable					8,391,000	9,185,000	$ 8,059,000
Less allowance for doubtful accounts					232,000	288,000	263,000
Total Accounts Receivable					8,159,000	8,897,000	7,796,000
Summary of allowance for doubtful accounts [Abstract]
Beginning balance					288,000	263,000	277,000
Allowance adjustments					103,000	215,000	195,000
Recoveries					47,000	41,000	64,000
Write off of uncollectible accounts					(206,000)	(231,000)	(273,000)
Ending balance					$ 232,000	288,000	263,000
Cash and Cash Equivalents [Abstract]
Maximum maturity period of temporary cash investments considered as cash equivalents					3 months
Restricted Stock [Member]
Stock Compensation Plans [Abstract]
Compensation costs					$ 192,000	423,000	92,000
Class A Stock [Member] | 2015 Equity Compensation Plan [Member]
Stock Compensation Plans [Abstract]
Number of share authorize under equity compensation plan (in shares)								331,500
Class A Stock [Member] | Unrestricted Stock [Member] | 2015 Equity Compensation Plan [Member]
Stock Compensation Plans [Abstract]
Granted, restricted stock awards (in shares)		6,568
Fair market value (in dollars per share)		$ 38.06
Class A Stock [Member] | Restricted Stock [Member] | 2015 Equity Compensation Plan [Member]
Stock Compensation Plans [Abstract]
Granted, restricted stock awards (in shares)	5,000		5,000
Fair market value (in dollars per share)	$ 38.51		$ 38.10
Award vesting period					1 year
Customer accounts receivable - water [Member]
Summary of changes in entity's accounts receivable [Abstract]
Gross accounts receivable					$ 5,585,000	5,487,000	5,437,000
Contractual amounts due from developers and other [Member]
Summary of changes in entity's accounts receivable [Abstract]
Gross accounts receivable					$ 2,806,000	$ 3,698,000	$ 2,622,000

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Amounts due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer) for goods or services (including trade receivables) that have been delivered or sold in the normal course of business.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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