Fair Value Disclosures - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value, option, changes in fair value, gains (losses)	$ (5,398)	$ (5,174)
Unadjusted net asset value of Star Asia Finance	34,375		39,998
Company's international valuation model of Star Asia value	24,136		30,169
Residential Loan [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets transfers out of level 3	267
Star Asia [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Discount rates used in determining fair value	6.65%		6.82%
Unadjusted net asset value of Star Asia Finance	$ 34,375		$ 39,998