SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Detail (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Significant Accounting Plicies [Line Items]
Certificates of Deposit and Cash	$ 0.7	$ 0.7
Inventory, Net	0.6	0.8
White Cliffs pipeline line fill crude oil inventory	1.1
Impairment of other property and equipment	0.0	0.8
Non-Oil and gas Depreciation, Depletion and Amortization	4.5	4.1	$ 4.0
Capitalized Interest	5.1	3.5	$ 1.7
Production Tax Liability	19.0	26.4
Debt Issuance Cost	11.4	13.7
7.75% Senior Notes [Member]
Significant Accounting Plicies [Line Items]
Debt Issuance Cost	$ 7.6	8.7
Debt Instrument, Interest Rate, Stated Percentage	7.75%
Revolving Credit Facility [Member]
Significant Accounting Plicies [Line Items]
Debt Issuance Cost	$ 3.6	4.3
3.25% Convertible Note [Member]
Significant Accounting Plicies [Line Items]
Debt Issuance Cost	$ 0.2	$ 0.7