Summary of Significant Accounting Policies (Policies)	3 Months Ended
Mar. 31, 2019
Accounting Policies [Abstract]
New Accounting Standards	New Accounting Standards Leases. On January 1, 2019, we adopted Accounting Standard Update (ASU) No. 2016-02, Leases (Topic 842), as amended, which affects aspects of accounting for lease agreements. Under the new standard, all leases in which we are the lessee, including operating leases, are recognized as lease assets and lease liabilities on the balance sheet. However, the adoption did not materially affect our statements of operations or statements of cash flows. For lease agreements in which we are the lessor, we have analyzed the impact of the standard and determined that there was no material impact to the recognition, measurement, or presentation of these revenues. Rooms revenues, which constitute the majority of our revenues, are considered short term leases. Additionally, we earn revenues from retail and office leases at our properties, which is included in other revenue. We adopted the standard using the effective date transition method with a cumulative-effect adjustment in the period of adoption. The standard provided several optional practical expedients for use in transition. We elected to use what the Financial Accounting Standards Board (“FASB”) has deemed the “package of practical expedients,” which allowed us not to reassess our previous conclusions about lease identification, lease classification and the accounting treatment for initial direct costs, and we elected not to reassess previous conclusions about land easements. Consequently, financial information will not be updated and disclosures required under the new standard will not be provided for dates and periods prior to January 1, 2019. Upon adoption, we recognized a right of use (“ROU”) asset and a related lease liability of $619 million and $628 million, respectively, with the prior year’s straight-line rent liability of $9 million reducing the ROU asset.

Summary of Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2019

Leases. On January 1, 2019, we adopted Accounting Standard Update (ASU) No. 2016-02, Leases (Topic 842), as amended, which affects aspects of accounting for lease agreements. Under the new standard, all leases in which we are the lessee, including operating leases, are recognized as lease assets and lease liabilities on the balance sheet. However, the adoption did not materially affect our statements of operations or statements of cash flows. For lease agreements in which we are the lessor, we have analyzed the impact of the standard and determined that there was no material impact to the recognition, measurement, or presentation of these revenues. Rooms revenues, which constitute the majority of our revenues, are considered short term leases. Additionally, we earn revenues from retail and office leases at our properties, which is included in other revenue. We adopted the standard using the effective date transition method with a cumulative-effect adjustment in the period of adoption. The standard provided several optional practical expedients for use in transition. We elected to use what the Financial Accounting Standards Board (“FASB”) has deemed the “package of practical expedients,” which allowed us not to reassess our previous conclusions about lease identification, lease classification and the accounting treatment for initial direct costs, and we elected not to reassess previous conclusions about land easements. Consequently, financial information will not be updated and disclosures required under the new standard will not be provided for dates and periods prior to January 1, 2019. Upon adoption, we recognized a right of use (“ROU”) asset and a related lease liability of $619 million and $628 million, respectively, with the prior year’s straight-line rent liability of $9 million reducing the ROU asset.