Basis of Presentation and Summary of Significant Accounting Policies (Policies)	9 Months Ended
Sep. 30, 2019
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The unaudited condensed consolidated financial statements reflect our financial position, results of operations and cash flows, in conformity with U.S. generally accepted accounting principles (“U.S. GAAP”). We have condensed or omitted certain information and footnote disclosures normally included in financial statements presented in accordance with U.S. GAAP. In our opinion, the accompanying unaudited condensed consolidated financial statements reflect all adjustments, including normal recurring items, considered necessary for a fair presentation of the interim periods. All significant intercompany transactions and balances within the financial statements have been eliminated. These financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto for the year ended December 31, 2018 included in our Annual Report on Form 10-K, filed with the SEC on February 28, 2019.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Interim results are not necessarily indicative of full year performance.
Reclassifications	Reclassifications Certain line items on the condensed consolidated statements of comprehensive income for the nine months ended September 30, 2018 have been reclassified to conform to the current period presentation.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements Adopted Accounting Standards In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2016-02 (“ASU 2016-02”), Leases (Topic 842), which supersedes existing lease accounting guidance in Leases (Topic 840) and generally requires all leases to be recognized on the statement of financial position. We adopted this ASU on January 1, 2019 using the optional transition method, which allows entities to initially apply the ASU at the adoption date without revising comparable periods. We consider an arrangement to contain a lease if it conveys the right to control the use of an identified asset for a period of time in exchange for compensation. We elected certain practical expedients that allowed us to utilize historical lease classifications and elected an accounting policy to continue accounting for leases with an initial term of 12 months and less using existing guidance for operating leases. We did not elect the practical expedient that allows us to use hindsight to reassess our probability of exercising renewal options; however, we did include any renewal options controlled by the lessor. On a prospective basis, lease terms will include both renewal options that we are reasonably certain to exercise as well as renewal options controlled by the lessor. Upon adoption, we recognized an operating lease right-of-use asset of $213 million representing the right to use land, buildings, and equipment over lease terms which include renewal options we have exercised, and renewal options controlled by the lessor, and a corresponding operating lease liability of $213 million representing the present value of our fixed lease payment obligations. We also recognized an $8 million impairment of the operating lease right-of-use asset associated with one of our previously impaired hotels as a cumulative effect of change in accounting principle within retained earnings. In addition, we reclassified $25 million of below market lease intangibles from intangibles, net and $8 million of deferred rent liabilities from other liabilities on our condensed consolidated balance sheet to the operating lease right-of-use asset. The discount rate used to calculate the operating lease right-of-use asset and operating lease liability was based on our estimated incremental borrowing rate at our adoption date of January 1, 2019. In August 2018, the FASB issued ASU No. 2018-15, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40), which adds recognition, measurement, and disclosure guidance on implementation costs of cloud computing arrangements. Implementation costs incurred by customers in cloud computing arrangements are deferred if they would be capitalized by customers in software license arrangements under the existing internal-use software guidance. We elected to early adopt this ASU as of January 1, 2019 on a prospective basis and there was no effect on our consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments”, which will replace the existing “incurred loss” approach with an “expected loss” model for instruments measured at amortized cost. For trade and other receivables, loans and other instruments, the forward looking “expected loss” model will generally result in the earlier recognition of allowances for losses. In November 2018, the FASB issued ASU No. 2018-19, “Codification Improvements to Topic 326, Financial Instruments-Credit Losses”, which clarifies that operating lease receivables accounted for under ASC 842 are not in the scope of ASU No. 2016-13. Both ASUs are effective January 1, 2020 and require new disclosures. Both ASUs require a modified retrospective approach. We are currently evaluating the effect that these ASUs will have on our consolidated financial statements.

Basis of Presentation and Summary of Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2019

The unaudited condensed consolidated financial statements reflect our financial position, results of operations and cash flows, in conformity with U.S. generally accepted accounting principles (“U.S. GAAP”). We have condensed or omitted certain information and footnote disclosures normally included in financial statements presented in accordance with U.S. GAAP. In our opinion, the accompanying unaudited condensed consolidated financial statements reflect all adjustments, including normal recurring items, considered necessary for a fair presentation of the interim periods. All significant intercompany transactions and balances within the financial statements have been eliminated.

These financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto for the year ended December 31, 2018 included in our Annual Report on Form 10-K, filed with the SEC on February 28, 2019.

Use of Estimates

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Interim results are not necessarily indicative of full year performance.

Reclassifications

Certain line items on the condensed consolidated statements of comprehensive income for the nine months ended September 30, 2018 have been reclassified to conform to the current period presentation.

Recently Issued Accounting Pronouncements

Adopted Accounting Standards

In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2016-02 (“ASU 2016-02”), Leases (Topic 842), which supersedes existing lease accounting guidance in Leases (Topic 840) and generally requires all leases to be recognized on the statement of financial position. We adopted this ASU on January 1, 2019 using the optional transition method, which allows entities to initially apply the ASU at the adoption date without revising comparable periods. We consider an arrangement to contain a lease if it conveys the right to control the use of an identified asset for a period of time in exchange for compensation. We elected certain practical expedients that allowed us to utilize historical lease classifications and elected an accounting policy to continue accounting for leases with an initial term of 12 months and less using existing guidance for operating leases. We did not elect the practical expedient that allows us to use hindsight to reassess our probability of exercising renewal options; however, we did include any renewal options controlled by the lessor. On a prospective basis, lease terms will include both renewal options that we are reasonably certain to exercise as well as renewal options controlled by the lessor. Upon adoption, we recognized an operating lease right-of-use asset of $213 million representing the right to use land, buildings, and equipment over lease terms which include renewal options we have exercised, and renewal options controlled by the lessor, and a corresponding operating lease liability of $213 million representing the present value of our fixed lease payment obligations. We also recognized an $8 million impairment of the operating lease right-of-use asset associated with one of our previously impaired hotels as a cumulative effect of change in accounting principle within retained earnings. In addition, we reclassified $25 million of below market lease intangibles from intangibles, net and $8 million of deferred rent liabilities from other liabilities on our condensed consolidated balance sheet to the operating lease right-of-use asset. The discount rate used to calculate the operating lease right-of-use asset and operating lease liability was based on our estimated incremental borrowing rate at our adoption date of January 1, 2019.

In August 2018, the FASB issued ASU No. 2018-15, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40), which adds recognition, measurement, and disclosure guidance on implementation costs of cloud computing arrangements. Implementation costs incurred by customers in cloud computing arrangements are deferred if they would be capitalized by customers in software license arrangements under the existing internal-use software guidance. We elected to early adopt this ASU as of January 1, 2019 on a prospective basis and there was no effect on our consolidated financial statements.

In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments”, which will replace the existing “incurred loss” approach with an “expected loss” model for instruments measured at amortized cost. For trade and other receivables, loans and other instruments, the forward looking “expected loss” model will generally result in the earlier recognition of allowances for losses. In November 2018, the FASB issued ASU No. 2018-19, “Codification Improvements to Topic 326, Financial Instruments-Credit Losses”, which clarifies that operating lease receivables accounted for under ASC 842 are not in the scope of ASU No. 2016-13. Both ASUs are effective January 1, 2020 and require new disclosures. Both ASUs require a modified retrospective approach. We are currently evaluating the effect that these ASUs will have on our consolidated financial statements.