LONG-TERM DEBT - Second lien credit agreement (Details)					1 Months Ended	12 Months Ended
	Apr. 01, 2019	Mar. 05, 2019 USD ($) series day $ / shares shares	Oct. 10, 2018 USD ($) shares	Apr. 26, 2017 USD ($) day tranche $ / shares	Nov. 30, 2017 USD ($)	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Mar. 04, 2019 $ / shares
Line of Credit Facility [Line Items]
Long-term debt						$ 115,000,000	$ 157,804,000
Gain on extinguishment of debt						$ 7,078,000
Second Lien Credit Agreement
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity				$ 125,000,000
Line of credit facility, number of tranches | tranche				2
Increase in borrowing capacity					$ 25,000,000
Additional borrowing capacity					$ 25,000,000
Debt instrument, interest rate, stated percentage								8.25%
Second Lien Term Loan
Line of Credit Facility [Line Items]
Debt instrument, convertible, threshold percentage of stock price trigger (at least)				150.00%
Second Lien Term Loan | Second Lien Credit Agreement
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity				$ 80,000,000
Delayed Draw Loans | Second Lien Credit Agreement
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity				$ 45,000,000
Conversion To Newly Issued Shares | Second Lien Term Loan
Line of Credit Facility [Line Items]
Conversion percentage of principal amount				70.00%
Conversion price (in dollars per share) | $ / shares				$ 5.50
Conversion To New Term Loan | Second Lien Term Loan
Line of Credit Facility [Line Items]
Conversion percentage of principal amount				30.00%
Minimum | Second Lien Term Loan
Line of Credit Facility [Line Items]
Threshold trading days | day				20
Maximum | Second Lien Term Loan
Line of Credit Facility [Line Items]
Threshold trading days | day				30
Private Placement
Line of Credit Facility [Line Items]
Mezzanine equity, stated value (in dollars per share) | $ / shares		$ 7.00
Varde Partners, Inc. | Private Placement
Line of Credit Facility [Line Items]
Mezzanine equity, shares issued (in shares) | shares		9,891,638	5,952,763
Number of new series of preferred stock | series		2
Amount canceled in exchange for equity issuance		$ 133,600,000
Mezzanine equity, new issues of stock		$ 18,600,000
Series D Preferred Stock
Line of Credit Facility [Line Items]
Mezzanine equity, shares issued (in shares) | shares						39,254	39,254
Redeemable preferred stock, dividend rate, percentage						8.25%	8.25%
Mezzanine equity, new issues of stock						$ 0
Mezzanine equity, stated value (in dollars per share) | $ / shares						$ 1,107	$ 1,021
Series D Preferred Stock | Private Placement | Maximum
Line of Credit Facility [Line Items]
Redeemable preferred stock, dividend rate, percentage	8.25%
Series D Preferred Stock | Varde Partners, Inc. | Private Placement
Line of Credit Facility [Line Items]
Mezzanine equity, shares issued (in shares) | shares			39,254
Redeemable preferred stock, dividend rate, percentage			8.25%
Series F Preferred Stock
Line of Credit Facility [Line Items]
Mezzanine equity, shares issued (in shares) | shares						55,000
Redeemable preferred stock, dividend rate, percentage						9.00%
Mezzanine equity, new issues of stock						$ 46,682,000
Mezzanine equity, stated value (in dollars per share) | $ / shares						$ 1,076
Series F Preferred Stock | Private Placement | Maximum
Line of Credit Facility [Line Items]
Redeemable preferred stock, dividend rate, percentage	9.00%
Series F Preferred Stock | Varde Partners, Inc. | Private Placement
Line of Credit Facility [Line Items]
Mezzanine equity, shares issued (in shares) | shares		55,000
Redeemable preferred stock, dividend rate, percentage		9.00%
Mezzanine equity, new issues of stock		$ 55,000,000
Series E Preferred Stock
Line of Credit Facility [Line Items]
Mezzanine equity, shares issued (in shares) | shares						60,000
Redeemable preferred stock, dividend rate, percentage						8.25%
Mezzanine equity, new issues of stock						$ 62,115,000
Mezzanine equity, stated value (in dollars per share) | $ / shares						$ 1,069
Series E Preferred Stock | Private Placement
Line of Credit Facility [Line Items]
Mezzanine equity, stated value (in dollars per share) | $ / shares		$ 1,000						$ 1.88
Series E Preferred Stock | Private Placement | Maximum
Line of Credit Facility [Line Items]
Redeemable preferred stock, dividend rate, percentage	8.25%
Series E Preferred Stock | Varde Partners, Inc. | Private Placement
Line of Credit Facility [Line Items]
Mezzanine equity, shares issued (in shares) | shares		60,000
Redeemable preferred stock, dividend rate, percentage		8.25%
Mezzanine equity, new issues of stock		$ 60,000,000
Second Lien Term Loan | 8.25% Second Lien Term Loan, due 2021, net of debt issuance costs and debt discount
Line of Credit Facility [Line Items]
Debt instrument, interest rate, stated percentage						8.25%	8.25%
Long-term debt						$ 0	$ 82,804,000
Second Lien Term Loan | 8.25% Second Lien Term Loan, due 2021, net of debt issuance costs and debt discount | Private Placement | Minimum
Line of Credit Facility [Line Items]
Threshold trading days | day		20
Second Lien Term Loan | 8.25% Second Lien Term Loan, due 2021, net of debt issuance costs and debt discount | Private Placement | Maximum
Line of Credit Facility [Line Items]
Threshold trading days | day		30
Second Lien Term Loan | 8.25% Second Lien Term Loan, due 2021, net of debt issuance costs and debt discount | Varde Partners, Inc.
Line of Credit Facility [Line Items]
Repayment of debt			$ 56,300,000
Long-term debt			$ 11,900,000
Additional Paid-In Capital
Line of Credit Facility [Line Items]
Gain on extinguishment of debt						$ 7,078,000