SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Stock-Based Compensation (Details)	3 Months Ended			12 Months Ended
	Mar. 31, 2018 USD ($) Plan Director $ / shares shares		Mar. 31, 2017 USD ($) shares	Dec. 31, 2016	Mar. 29, 2018 $ / shares
Share-Based Compensation [Abstract]
Number of stock based compensation plans | Plan	1
Additional Disclosures [Abstract]
Proceeds from stock option exercises	$ 132,400	[1]	$ 258,250
Closing price of common stock (in dollars per share) | $ / shares					$ 44.34
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 33,000		$ 33,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of board of directors granted options | Director	2
Options grant date fair value	$ 540,000
Volatility rate	39.60%
Risk free rate	2.62%
Expected term	6 years 3 months
Stock Options Activity [Roll Forward]
Outstanding, beginning of period (in shares) | shares	232,000
Grants (in shares) | shares	30,000		0
Exercised (in shares) | shares	(10,000)
Forfeitures or expirations (in shares) | shares	0
Outstanding, end of period (in shares) | shares	252,000
Exercisable, end of period (in shares) | shares	207,000
Weighted Average Exercise Price [Roll Forward]
Outstanding, beginning of period (in dollars per share) | $ / shares	$ 21.56
Grants (in dollars per share) | $ / shares	41.82
Exercised (in dollars per share) | $ / shares	13.24
Forfeitures or expirations (in dollars per share) | $ / shares	0
Outstanding, end of period (in dollars per share) | $ / shares	24.30
Exercisable, end of period (in dollars per share) | $ / shares	$ 20.80
Weighted Average Remaining Contractual Term [Roll Forward]
Outstanding	3 years 3 months 14 days			2 years 6 months 7 days
Grants	0 years
Exercised	0 years
Forfeitures or expirations	0 years
Exercisable	2 years 14 days
Aggregate Intrinsic Value [Roll Forward]
Outstanding, beginning of period	$ 5,050,990
Grants	0
Exercised	0
Forfeitures or expirations	0
Outstanding, end of period	5,049,910
Exercisable, end of period	4,873,810
Additional Disclosures [Abstract]
Proceeds from stock option exercises	132,000		$ 258,000
Unrecognized compensation cost	$ 648,000
Recognized compensation period	3 years 5 months 12 days

[1] As of January 1, 2018, the Company adopted the requirements of ASC 606 using the modified retrospective adoption method, and as a result, there is a lack of comparability of certain amounts to the prior periods presented. See Note 2 for additional discussion.