Summary of Significant Accounting Policies - Carrying Value and Classification of Related Assets and Maximum Exposure to Loss (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014
Loans, net [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure	$ 256,193
Mortgage and other loans [Member]
Variable Interest Entity [Line Items]
Carrying Amount	210,528
Equity investments [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure	47,095
Other assets [Member]
Variable Interest Entity [Line Items]
Carrying Amount	$ 5,293