Summary of Significant Accounting Policies - Carrying Value and Classification of Related Assets and Maximum Exposure to Loss (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015
Mortgage and other loans [Member]
Variable Interest Entity [Line Items]
Carrying Amount	$ 212,196
Loans, net [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure	264,397
Other assets [Member]
Variable Interest Entity [Line Items]
Carrying Amount	5,324
Equity investments [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure	$ 59,228