Long-Term Debt - Additional Information (Details) | Apr. 26, 2019USD ($) | Mar. 15, 2019USD ($) | May 04, 2018 | Nov. 30, 2017USD ($) | Mar. 31, 2019USD ($)redetermination | Dec. 31, 2018USD ($) | Nov. 02, 2018USD ($) |
Senior Notes | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Debt discount | | | | | $ 3,825,000 | $ 0 | |
Percentage of principal amount, eligible to be redeemed | | | | | 35.00% | | |
Redemption price percentage | | | | | 100.00% | | |
Percentage of principal amount, redeemable | | | | | 65.00% | | |
Percentage of principal amount, event of default | | | | | 25.00% | | |
Revolving Credit Facility | Line of Credit | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Borrowing base | | | | | $ 1,000,000,000 | | $ 1,000,000,000 |
Elected commitments | | | | | 800,000,000 | | |
Line of credit, term | | | 5 years | | | | |
Borrowings, outstanding amount | | | | | 0 | | |
Remaining borrowing capacity, net of current borrowings outstanding | | | | | 799,200,000 | | |
Maximum borrowing base | | | | | $ 1,500,000,000 | | |
Number of optional borrowing base redeterminations | redetermination | | | | | 2 | | |
Revolving Credit Facility | Line of Credit | Subsequent Event | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Borrowing base | $ 1,200,000,000 | | | | | | |
Letter of Credit | Line of Credit | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Letters of credit outstanding | | | | | $ 800,000 | | |
Minimum | Revolving Credit Facility | Line of Credit | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Commitment fee percentage on unused amounts | | | | | 0.375% | | |
Debt instrument, covenant, minimum current ratio | | | | | 1 | | |
Maximum | Revolving Credit Facility | Line of Credit | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Commitment fee percentage on unused amounts | | | | | 0.50% | | |
Debt instrument, covenant, maximum leverage ratio | | | | | 4 | | |
Maximum | Revolving Credit Facility | Line of Credit | Subsequent Event | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Debt instrument, covenant, maximum leverage ratio | 3 | | | | | | |
Senior Notes Due 2027 | Senior Notes | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Long-term debt | | $ 500,000,000 | | | | | |
Interest rate, stated percentage | | 6.875% | | | 6.875% | | |
Private placement price as percentage of par | | 99.235% | | | | | |
Proceeds from borrowings, net of issuance costs | | $ 489,000,000 | | | | | |
Debt discount | | 3,800,000 | | | | | |
Debt issuance costs | | $ 7,200,000 | | | | | |
Redemption price percentage | | 106.875% | | | | | |
Senior Notes Due 2026 | Senior Notes | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Long-term debt | | | | $ 400,000,000 | | | |
Interest rate, stated percentage | | | | 5.375% | 5.375% | | |
Proceeds from borrowings, net of issuance costs | | | | $ 391,000,000 | | | |
Debt issuance costs | | | | $ 9,000,000 | | | |
Redemption price percentage | | | | 105.375% | | | |
Percentage of principal amount, change in control | | | | 101.00% | | | |
Adjusted For Statutory Reserve Requirements - London Interbank Offered Rate (LIBOR) | Revolving Credit Facility | Line of Credit | Subsequent Event | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Decrease to basis spread on variable rate after redetermination | 0.25% | | | | | | |
Adjusted For Statutory Reserve Requirements - London Interbank Offered Rate (LIBOR) | Minimum | Revolving Credit Facility | Line of Credit | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Basis spread on variable rate | | | | | 1.50% | | |
Adjusted For Statutory Reserve Requirements - London Interbank Offered Rate (LIBOR) | Minimum | Revolving Credit Facility | Line of Credit | Subsequent Event | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Basis spread on variable rate | 1.25% | | | | | | |
Adjusted For Statutory Reserve Requirements - London Interbank Offered Rate (LIBOR) | Maximum | Revolving Credit Facility | Line of Credit | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Basis spread on variable rate | | | | | 2.50% | | |
Adjusted For Statutory Reserve Requirements - London Interbank Offered Rate (LIBOR) | Maximum | Revolving Credit Facility | Line of Credit | Subsequent Event | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Basis spread on variable rate | 2.25% | | | | | | |
Federal Funds Effective Swap Rate | Revolving Credit Facility | Line of Credit | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Basis spread on variable rate | | | | | 0.50% | | |
One-Month London Interbank Offered Rate (LIBOR) | Revolving Credit Facility | Line of Credit | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Basis spread on variable rate | | | | | 1.00% | | |
London Interbank Offered Rate (LIBOR) | Revolving Credit Facility | Line of Credit | Subsequent Event | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Decrease to basis spread on variable rate after redetermination | 0.25% | | | | | | |
London Interbank Offered Rate (LIBOR) | Minimum | Revolving Credit Facility | Line of Credit | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Basis spread on variable rate | | | | | 0.50% | | |
London Interbank Offered Rate (LIBOR) | Minimum | Revolving Credit Facility | Line of Credit | Subsequent Event | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Basis spread on variable rate | 0.25% | | | | | | |
London Interbank Offered Rate (LIBOR) | Maximum | Revolving Credit Facility | Line of Credit | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Basis spread on variable rate | | | | | 1.50% | | |
London Interbank Offered Rate (LIBOR) | Maximum | Revolving Credit Facility | Line of Credit | Subsequent Event | | | | | | | |
Debt Instrument [Line Items] | | | | | | | |
Basis spread on variable rate | 1.25% | | | | | | |