Loans Held-for-Sale - Additional Information (Detail) (USD $)	12 Months Ended		3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recovery of valuation allowance on loans held-for-sale	$ 1,300,000	$ 1,259,000
Loans held-for-sale	0	0
Loans Held-for-Sale, Net [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount reclassified on subordinate mortgage loan			4,600,000
Recovery of valuation allowance on loans held-for-sale		(1,259,000)
Subordinate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount reclassified on subordinate mortgage loan			$ 6,600,000