CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
REVENUES
Oil sales	$ 216.0	$ 207.7	$ 437.7	$ 351.5
Gas sales	134.2	79.2	268.7	164.3
NGL sales	22.8	22.8	51.8	36.4
Other revenue	2.7	(0.5)	6.7	1.8
Purchased oil and gas sales	8.0	24.5	38.9	41.0
Total Revenues	383.7	333.7	803.8	595.0
OPERATING EXPENSES
Purchased oil and gas expense	9.1	26.8	38.5	43.7
Lease operating expense	70.0	52.6	139.2	112.6
Transportation and processing costs	72.2	69.5	142.4	143.1
Gathering and other expense	1.8	1.6	3.3	2.9
General and administrative	31.3	42.9	64.9	91.4
Production and property taxes	28.5	20.7	57.6	38.5
Depreciation, depletion and amortization	191.5	209.7	383.3	449.7
Exploration expenses	0.0	0.4	0.4	0.7
Impairment	0.0	0.8	0.1	1,183.2
Total operating expenses	404.4	425.0	829.7	2,065.8
Net gain (loss) from asset sales	19.8	(0.8)	19.8	(0.3)
OPERATING INCOME (LOSS)	(0.9)	(92.1)	(6.1)	(1,471.1)
Realized and unrealized gains (losses) on derivative contracts (Note 7)	106.7	(180.5)	267.6	(129.6)
Interest and other income (expense)	1.8	(1.1)	2.4	1.0
Interest expense	(34.9)	(36.6)	(68.7)	(73.3)
INCOME (LOSS) BEFORE INCOME TAXES	72.7	(310.3)	195.2	(1,673.0)
Income tax (provision) benefit	(27.3)	113.3	(72.9)	612.2
NET INCOME (LOSS)	$ 45.4	$ (197.0)	$ 122.3	$ (1,060.8)
Earnings per common share
Earnings Per Share, Basic	$ 0.19	$ (0.90)	$ 0.51	$ (5.21)
Earnings Per Share, Diluted	$ 0.19	$ (0.90)	$ 0.51	$ (5.21)
Weighted-average common shares outstanding
Used in basic calculation (in shares)	240.5	217.7	240.4	203.7
Used in diluted calculation (in shares)	240.6	217.7	240.5	203.7
Dividends per common share (in dollars per share)	$ 0.00	$ 0.00	$ 0.00	$ 0.00