SIGNIFICANT ACCOUNTING POLICIES - Recently Adopted Accounting Pronouncements (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle
Accumulated other comprehensive loss		$ (1,000)	$ (104,000)
Retained earnings		162,616,000	$ 128,555,000
Right-of-use assets		11,957,000
Operating lease liability		12,476,000
2016-02
New Accounting Pronouncements or Change in Accounting Principle
Right-of-use assets	$ 13,600,000
Operating lease liability	14,000,000
Cumulative effect decrease to retained earnings	$ 255,000	$ 255,000
2018-02
New Accounting Pronouncements or Change in Accounting Principle
Accumulated other comprehensive loss				$ (13,000,000)
Retained earnings				$ 13,000,000