|
Risk Management Activities (Details) (USD $)
|
3 Months Ended |
|
|
Mar. 31, 2013
|
Mar. 31, 2012
|
Dec. 31, 2012
|
| Derivatives, Fair Value [Line Items] |
|
|
|
| Derivatives Assets, Current |
$ 32,711,000 |
|
$ 166,135,000 |
| Derivative Liabilities, Current |
14,108,000 |
|
7,617,000 |
| Foreign Currency Exchange Rate Derivative [Abstract] |
|
|
|
| After-Tax Net Impact Other Comprehensive Income Increase (Decrease) From The Foreign Currency Swap |
1,700,000 |
1,500,000 |
|
| Interest Rate Derivative [Abstract] |
|
|
|
| Interest Rate Swap, Notional Amount |
350,000,000 |
|
|
| After-Tax Net Impact Other Comprehensive Income Increase (Decrease) From Interest Rate Swap |
500,000 |
(400,000) |
|
| Derivative Collateral [Abstract] |
|
|
|
| Collateral Held on Derivative |
0 |
|
6,000,000 |
|
Crude Oil and Natural Gas Derivative Contracts [Member] | Assets From Price Risk Management Activities [Member]
|
|
|
|
| Derivatives, Fair Value [Line Items] |
|
|
|
| Derivatives Assets, Current |
33,000,000 |
|
166,000,000 |
| Derivative Assets, Current, Gross |
72,000,000 |
|
257,000,000 |
| Derivative Liabilities, Current, Gross |
39,000,000 |
|
91,000,000 |
|
Crude Oil and Natural Gas Derivative Contracts [Member] | Liabilities From Price Risk Management Activities [Member]
|
|
|
|
| Derivatives, Fair Value [Line Items] |
|
|
|
| Derivative Liabilities, Current |
14,000,000 |
|
8,000,000 |
| Derivative Assets, Current, Gross |
14,000,000 |
|
9,000,000 |
| Derivative Liabilities, Current, Gross |
28,000,000 |
|
17,000,000 |
|
Crude Oil and Natural Gas Derivative Contracts [Member] | Other Liabilities [Member]
|
|
|
|
| Derivatives, Fair Value [Line Items] |
|
|
|
| Other Liabilities |
45,000,000 |
|
13,000,000 |
| Derivative Assets, Noncurrent, Gross |
11,000,000 |
|
|
| Derivative Liabilities, Noncurrent, Gross |
56,000,000 |
|
13,000,000 |
|
Foreign Currency Swap [Member] | Other Current Liabilities [Member]
|
|
|
|
| Derivatives, Fair Value [Line Items] |
|
|
|
| Derivative Liabilities, Current |
49,000,000 |
|
0 |
|
Foreign Currency Swap [Member] | Other Liabilities [Member]
|
|
|
|
| Derivatives, Fair Value [Line Items] |
|
|
|
| Other Liabilities |
0 |
|
55,000,000 |
|
Interest Rate Swap [Member] | Other Current Liabilities [Member]
|
|
|
|
| Derivatives, Fair Value [Line Items] |
|
|
|
| Derivative Liabilities, Current |
3,000,000 |
|
0 |
|
Interest Rate Swap [Member] | Other Liabilities [Member]
|
|
|
|
| Derivatives, Fair Value [Line Items] |
|
|
|
| Other Liabilities |
$ 0 |
|
$ 4,000,000 |
|
Crude Oil Derivative Contracts January (closed) [Member]
|
|
|
|
| Derivative [Line Items] |
|
|
|
| Volume (Bbld) |
101,000 |
|
|
| Derivative Weighted Average Price Crude Oil ($/Bbl) |
99.29 |
|
|
|
Crude Oil Derivative Contracts February - March (closed) [Member]
|
|
|
|
| Derivative [Line Items] |
|
|
|
| Volume (Bbld) |
109,000 |
|
|
| Derivative Weighted Average Price Crude Oil ($/Bbl) |
99.17 |
|
|
|
Crude Oil Derivative Contracts April [Member]
|
|
|
|
| Derivative [Line Items] |
|
|
|
| Volume (Bbld) |
109,000 |
|
|
| Derivative Weighted Average Price Crude Oil ($/Bbl) |
99.17 |
|
|
|
Crude Oil Derivative Contracts May - June [Member]
|
|
|
|
| Derivative [Line Items] |
|
|
|
| Volume (Bbld) |
101,000 |
|
|
| Derivative Weighted Average Price Crude Oil ($/Bbl) |
99.29 |
|
|
|
Crude Oil Derivative Contracts July - December [Member]
|
|
|
|
| Derivative [Line Items] |
|
|
|
| Volume (Bbld) |
93,000 |
|
|
| Derivative Weighted Average Price Crude Oil ($/Bbl) |
98.44 |
|
|
| Volumes (Bbld) - Derivative Option Contracts |
62,000 |
|
|
| Average Price ($/Bbl) - Derivative Option Contracts |
100.24 |
|
|
|
Crude Oil Derivative Contracts May - July [Member]
|
|
|
|
| Derivative [Line Items] |
|
|
|
| Volumes (Bbld) - Derivative Option Contracts |
8,000 |
|
|
| Average Price ($/Bbl) - Derivative Option Contracts |
97.66 |
|
|
|
Crude Oil Derivative Contracts Year Two January - December [Member]
|
|
|
|
| Derivative [Line Items] |
|
|
|
| Volume (Bbld) |
40,000 |
|
|
| Derivative Weighted Average Price Crude Oil ($/Bbl) |
95.77 |
|
|
|
Crude Oil Derivative Contracts Year Two January - June [Member]
|
|
|
|
| Derivative [Line Items] |
|
|
|
| Volumes (Bbld) - Derivative Option Contracts |
54,000 |
|
|
| Average Price ($/Bbl) - Derivative Option Contracts |
98.91 |
|
|
|
Crude Oil Derivative Contracts Year Two July - December [Member]
|
|
|
|
| Derivative [Line Items] |
|
|
|
| Volumes (Bbld) - Derivative Option Contracts |
40,000 |
|
|
| Average Price ($/Bbl) - Derivative Option Contracts |
95.77 |
|
|
|
Natural Gas Derivative Contracts January - April (closed) [Member]
|
|
|
|
| Derivative [Line Items] |
|
|
|
| Volume (MMBtud) |
150,000 |
|
|
| Derivative Weighted Average Price Natural Gas ($/MMBtu) |
4.79 |
|
|
|
Natural Gas Derivative Contracts May - December [Member]
|
|
|
|
| Derivative [Line Items] |
|
|
|
| Volume (MMBtud) |
150,000 |
|
|
| Derivative Weighted Average Price Natural Gas ($/MMBtu) |
4.79 |
|
|
| Volumes (MMBtud) - Derivative Option Contracts |
150,000 |
|
|
| Average Price ($/MMBtu) - Derivative Option Contracts |
4.79 |
|
|
|
Natural Gas Derivative Contracts Year Two January - December [Member]
|
|
|
|
| Derivative [Line Items] |
|
|
|
| Volume (MMBtud) |
100,000 |
|
|
| Derivative Weighted Average Price Natural Gas ($/MMBtu) |
4.48 |
|
|
| Volumes (MMBtud) - Derivative Option Contracts |
250,000 |
|
|
| Average Price ($/MMBtu) - Derivative Option Contracts |
4.66 |
|
|