Notes Receivable - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended	9 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Sep. 07, 2012	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable, unamortized discounts	$ 27,000,000		$ 27,000,000		$ 12,000,000
Notes receivable reserve representing an allowance for credit losses	95,000,000		95,000,000		90,000,000
Investment in impaired loans	108,000,000		108,000,000		99,000,000
Investment in impaired loans with no related allowance for credit losses	13,000,000		13,000,000		9,000,000
Average investment in impaired loans	105,000,000	101,000,000	104,000,000	99,000,000
Notes receivable, past due	0		0
Mezzanine Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mezzanine loans	85,000,000		85,000,000
Notes receivable, unamortized discounts	$ (15,000,000)		$ (15,000,000)