CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
REVENUES
Oil and condensate, gas and NGL sales	$ 409.8	$ 385.2
Other revenue	5.0	4.0
Purchased oil and gas sales	14.1	30.9
Total Revenues	428.9	420.1
OPERATING EXPENSES
Purchased oil and gas expense	15.5	29.4
Lease operating expense	72.5	69.2
Transportation and processing costs	34.0	70.2
Gathering and other expense	2.8	1.5
General and administrative	60.1	33.6
Production and property taxes	28.9	29.1
Depreciation, depletion and amortization	196.5	191.8
Exploration expenses	0.0	0.4
Impairment	0.7	0.1
Total Operating Expenses	411.0	425.3
Net gain (loss) from asset sales	3.5	0.0
OPERATING INCOME (LOSS)	21.4	(5.2)
Realized and unrealized gains (losses) on derivative contracts (Note 7)	(53.2)	160.9
Interest and other income (expense)	(0.7)	0.6
Interest expense	(35.0)	(33.8)
INCOME (LOSS) BEFORE INCOME TAXES	(67.5)	122.5
Income tax (provision) benefit	13.9	(45.6)
Net income (loss)	$ (53.6)	$ 76.9
Earnings (loss) per common share
Basic	$ 0	$ 0.32
Diluted	$ 0	$ 0.32
Weighted-average common shares outstanding
Used in basic calculation	240.9	240.2
Used in diluted calculation	240.9	240.3
Dividends per common share	$ 0	$ 0.00