Fair Value Measurements - Fair Value of Certain Financial Instrument and Hierarchy Level Used to Estimate Fair Values (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Carrying amount [Member] | SF CMBS Loan [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loan	$ 725	$ 725
Carrying amount [Member] | HHV CMBS Loan [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loan	1,275	1,275
Carrying amount [Member] | Term Loan [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loan	750	750
Carrying amount [Member] | Mortgage Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loan	207	207
Carrying amount [Member] | Unsecured Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Unsecured notes		55
Fair Value [Member] | SF CMBS Loan [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loan	721	725
Fair Value [Member] | HHV CMBS Loan [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loan	1,256	1,275
Fair Value [Member] | Term Loan [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loan	749	750
Fair Value [Member] | Mortgage Loans [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loan	$ 204	208
Fair Value [Member] | Unsecured Notes [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Unsecured notes		$ 57