CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
OPERATING ACTIVITIES
Net income (loss)	$ (1,060.8)	$ (131.9)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, depletion and amortization	449.7	411.2
Deferred income taxes	(559.9)	(29.4)
Impairment	1,183.2	20.5
Share-based compensation	19.1	15.6
Other Operating Activities, Curtailment Loss	0.0	11.2
Amortization of debt issuance costs and discounts	3.2	3.3
Net (gain) loss from asset sales	0.3	6.0
Unrealized (gains) losses on marketable securities	(0.5)	0.0
Unrealized (gains) losses on derivative contracts	243.5	181.8
Changes in operating assets and liabilities	(58.2)	(490.9)
Net Cash Provided by (Used in) Operating Activities	219.6	(2.6)
INVESTING ACTIVITIES
Property acquisitions	(23.6)	0.0
Acquisition Deposit Held In Escrow	(30.0)	0.0
Property, plant and equipment, including dry exploratory well expense	(276.6)	(651.3)
Proceeds from disposition of assets	23.7	(2.4)
Net Cash Provided by (Used in) Investing Activities	(306.5)	(653.7)
FINANCING ACTIVITIES
Checks outstanding in excess of cash balances	(29.8)	(47.3)
Treasury stock repurchases	(3.1)	(1.9)
Other capital contributions	0.2	(0.1)
Dividends paid	0.0	(7.1)
Proceeds from issuance of common stock, net	781.6	0.0
Excess tax (provision) benefit on share-based compensation	0.2	(1.8)
Net Cash Provided by (Used in) Financing Activities	749.1	(58.2)
Change in cash and cash equivalents	662.2	(714.5)
Beginning cash and cash equivalents	376.1	1,160.1
Ending cash and cash equivalents	1,038.3	445.6
Supplemental Disclosures:
Cash paid for interest, net of capitalized interest	68.6	69.7
Cash paid for income taxes	32.4	548.5
Non-cash Investing Activities
Change in capital expenditure accruals and other non-cash adjustments	$ (27.7)	$ (91.6)