Recorded Investment and Past Due Status of Residential Loans Collectively Evaluated for Impairment (Detail) (Residential Loans, USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	$ 1,705,306	$ 1,779,161
Collectively Evaluated for Impairment
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	31,308	34,187
60-89 Days Past Due	6,942	13,248
90 + Days Past Due	81,699	79,010
Current	$ 1,585,357	$ 1,652,716