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v3.10.0.1

Subsequent Events (Details) | 1 Months Ended | 2 Months Ended | 12 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | ---
Feb. 28, 2019 MMBTU $ / MMBTU | Feb. 28, 2019 $ / MMBTU shares | Dec. 31, 2018 shares | Jan. 31, 2019 USD ($) | May 31, 2018 USD ($) | Jan. 31, 2018 USD ($)
Derivative [Line Items] |  |  |  |  |  |
Stock repurchase program, authorized amount | $ |  |  |  |  | $ 200,000,000 | $ 100,000,000
Stock repurchased and retired during period (shares) | shares |  |  | 20,700,000 |  |  |
Subsequent event |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |
Stock repurchase program, authorized amount | $ |  |  |  | $ 400,000,000.0 |  |
Stock repurchased and retired during period (shares) | shares |  | 0 |  |  |  |
Natural Gas Basis Swap 2020 | Subsequent event |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |
Daily Volume (MMBtu/day) | MMBTU | 10,000 |  |  |  |  |
Differential of MMBtu (in usd per MMbtu) | $ / MMBTU | 0.535 | 0.535 |  |  |  |

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