v3.7.0.1

Equity Method Investments (Details) $ in Thousands |  |  | 3 Months Ended | 6 Months Ended
--- | --- | --- | --- | ---
Feb. 10, 2017 USD ($) shares | Feb. 06, 2017 | Jun. 30, 2017 USD ($) | Jun. 30, 2016 USD ($) mi | Jun. 30, 2017 USD ($) | Jun. 30, 2016 USD ($) mi
Equity Method Investment |  |  |  |  |  |
Contribution to joint venture |  |  |  |  | $ 191,364 | $ 45,044
Investments in unconsolidated affiliates |  |  |  |  |  |
Balance at beginning of period |  |  |  |  | 68,299 |
Initial investment |  |  |  |  | 153,770 |
Additional investment |  |  |  |  | 37,594 |
Equity in net income (loss) of unconsolidated affiliates |  |  | $ 3,623 | $ 484 | 5,854 | $ 484
Distributions from unconsolidated affiliates |  |  |  |  | (5,820) |
Balance at end of period |  |  | 259,697 |  | 259,697 |
Common Unitholders Public |  |  |  |  |  |
Equity Method Investment |  |  |  |  |  |
Sale of units to public (in shares) | shares | 6,900,000 |  |  |  |  |
Net proceeds from sale of units | $ 223,000 |  |  |  |  |
Appalachia Joint venture |  |  |  |  |  |
Equity Method Investment |  |  |  |  |  |
Ownership percentage |  | 50.00% |  |  |  |
Percentage of interest held by joint venture in third party fractionator in Ohio |  | 33.33% |  |  |  |
Investments in unconsolidated affiliates |  |  |  |  |  |
Initial investment |  |  |  |  | 153,770 |
Additional investment |  |  |  |  | 37,594 |
Equity in net income (loss) of unconsolidated affiliates |  |  |  |  | 769 |
Balance at end of period |  |  | $ 192,133 |  | $ 192,133 |
Appalachia Joint venture | MarkWest |  |  |  |  |  |
Equity Method Investment |  |  |  |  |  |
Ownership percentage |  | 50.00% | 50.00% |  | 50.00% |
Stonewall Gas Gathering LLC |  |  |  |  |  |
Equity Method Investment |  |  |  |  |  |
Ownership percentage |  |  | 15.00% | 15.00% | 15.00% | 15.00%
Number of miles | mi |  |  |  | 67 |  | 67
Investments in unconsolidated affiliates |  |  |  |  |  |
Balance at beginning of period |  |  |  |  | $ 68,299 |
Equity in net income (loss) of unconsolidated affiliates |  |  |  |  | 5,085 |
Distributions from unconsolidated affiliates |  |  |  |  | (5,820) |
Balance at end of period |  |  | $ 67,564 |  | $ 67,564 |

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