OIL AND NATURAL GAS OPERATIONS (Unaudited) - Oil and Gas Operations (Details)	12 Months Ended
	Dec. 31, 2016 MMBoe MBbls MMcf	Dec. 31, 2015 MMBoe MBbls MMcf	Dec. 31, 2014 MMBoe MBbls MMcf
Proved Developed and Undeveloped Reserves [Roll Forward]
Proved reserves at beginning of period, total (in mmboe) | MMBoe	354.7	372.7	347.8
Revisions of previous estimates, total (in mmboe) | MMBoe	(26.0)	(58.9)	(75.7)
Purchases, total (in mmboe) | MMBoe	0.1	0	0.1
Extensions and discoveries, total (in mmboe) | MMBoe	64.1	132.6	130.0
Production, total (in mmboe) | MMBoe	(21.6)	(24)	(25.8)
Sales, total (in mmboe) | MMBoe	(55.0)	(67.7)	(3.7)
Proved reserves at end of period, total (in mmboe) | MMBoe	316.3	354.7	372.7
Proved developed reserves at end of period (in mmboe) | MMBoe	162.1	184	264.5
Proved undeveloped reserves at end of period (in mmboe) | MMBoe	154.2	170.7	108.2
Oil Reserves
Proved Developed and Undeveloped Reserves [Roll Forward]
Proved reserves at beginning of period (in mbbls and mmcf)	210,691	181,227	164,870
Revisions of previous estimates (in mbbls and mmcf)	(17,840)	(39,537)	(48,548)
Purchases (in mbbls and mmcf)	103	2	88
Extensions and discoveries (in mbbls and mmcf)	45,129	83,319	76,722
Production (in mbbls and mmcf)	(13,213)	(14,023)	(11,818)
Sales (in mbbls and mmcf)	(25,295)	(297)	(87)
Proved reserves at end of period (in mbbls and mmcf)	199,575	210,691	181,227
Proved developed reserves at end of period (in mbbls and mmcf)	101,202	108,319	118,697
Proved undeveloped reserves at end of period (in mbbls and mmcf)	98,373	102,372	62,530
Natural Gas Liquids Reserves
Proved Developed and Undeveloped Reserves [Roll Forward]
Proved reserves at beginning of period (in mbbls and mmcf)	71,713	73,463	63,011
Revisions of previous estimates (in mbbls and mmcf)	(6,800)	(11,979)	(15,165)
Purchases (in mbbls and mmcf)	21	1	26
Extensions and discoveries (in mbbls and mmcf)	10,480	25,530	29,695
Production (in mbbls and mmcf)	(3,892)	(4,065)	(4,104)
Sales (in mbbls and mmcf)	(13,476)	(11,237)	0
Proved reserves at end of period (in mbbls and mmcf)	58,046	71,713	73,463
Proved developed reserves at end of period (in mbbls and mmcf)	29,767	36,374	47,621
Proved undeveloped reserves at end of period (in mbbls and mmcf)	28,279	35,339	25,842
Natural Gas Reserves
Proved Developed and Undeveloped Reserves [Roll Forward]
Proved reserves at beginning of period (in mbbls and mmcf) | MMcf	433,904	707,926	719,725
Revisions of previous estimates (in mbbls and mmcf) | MMcf	(7,779)	(44,176)	(71,806)
Purchases (in mbbls and mmcf) | MMcf	89	2	116
Extensions and discoveries (in mbbls and mmcf) | MMcf	50,780	143,022	141,209
Production (in mbbls and mmcf) | MMcf	(27,204)	(35,604)	(59,562)
Sales (in mbbls and mmcf) | MMcf	(97,542)	(337,266)	(21,756)
Proved reserves at end of period (in mbbls and mmcf) | MMcf	352,248	433,904	707,926
Proved developed reserves at end of period (in mbbls and mmcf) | MMcf	187,117	236,112	589,074
Proved undeveloped reserves at end of period (in mbbls and mmcf) | MMcf	165,131	197,792	118,852