Fair Value of Financial Instruments - Equity Interest in Ernest and Related Loans Measured at Fair Value on Recurring Basis (Detail) (Fair Value Measurements, Recurring, USD $) In Thousands, unless otherwise specified	Sep. 30, 2013
Financial Instruments Measured At Fair Value On Recurring Basis [Line Items]
Fair Value	$ 201,583
Cost	201,583
Mortgage loans | Mortgage Loans
Financial Instruments Measured At Fair Value On Recurring Basis [Line Items]
Fair Value	100,000
Cost	100,000
Acquisition Loan | Other loans
Financial Instruments Measured At Fair Value On Recurring Basis [Line Items]
Fair Value	98,283
Cost	98,283
Equity investments | Other assets
Financial Instruments Measured At Fair Value On Recurring Basis [Line Items]
Fair Value	3,300
Cost	$ 3,300