Goodwill	9 Months Ended
Sep. 30, 2018
Goodwill
Goodwill	Note 7—Goodwill Impairment—We conduct goodwill impairment testing annually and when events occur or circumstances change that would more likely than not reduce the fair value of our reporting unit below its carrying amount. During the three months ended June 30, 2018, we classified as held for sale and impaired three ultra‑deepwater floaters (see Note 6—Drilling Fleet). We identified the impairment of these assets included in our single contract drilling services reporting unit as a trigger to test the recoverability of goodwill. As a result, we performed an interim goodwill impairment test as of June 30, 2018, and we determined that the goodwill associated with our contract drilling services reporting unit was fully impaired. In the nine months ended September 30, 2018, we recognized a loss of $462 million ($1.02 per diluted share), which had no tax effect, associated with the impairment of the full balance of our goodwill. We estimated the fair value of the contract drilling services reporting unit using the income approach. Our estimate of fair value required us to use significant unobservable inputs, representative of a Level 3 fair value measurement, including assumptions related to the future performance of the reporting unit, such as future commodity prices, projected demand for our services, rig availability and dayrates.

Note 7—Goodwill

Impairment—We conduct goodwill impairment testing annually and when events occur or circumstances change that would more likely than not reduce the fair value of our reporting unit below its carrying amount. During the three months ended June 30, 2018, we classified as held for sale and impaired three ultra‑deepwater floaters (see Note 6—Drilling Fleet). We identified the impairment of these assets included in our single contract drilling services reporting unit as a trigger to test the recoverability of goodwill. As a result, we performed an interim goodwill impairment test as of June 30, 2018, and we determined that the goodwill associated with our contract drilling services reporting unit was fully impaired. In the nine months ended September 30, 2018, we recognized a loss of $462 million ($1.02 per diluted share), which had no tax effect, associated with the impairment of the full balance of our goodwill. We estimated the fair value of the contract drilling services reporting unit using the income approach. Our estimate of fair value required us to use significant unobservable inputs, representative of a Level 3 fair value measurement, including assumptions related to the future performance of the reporting unit, such as future commodity prices, projected demand for our services, rig availability and dayrates.