Bank subsidiary (Details 13)	12 Months Ended
	Dec. 31, 2011 Y
Residential loan
Troubled debt restructurings
Period of deferral of principal repayments (in years)	1
Period of temporary reduction in principal and/ or interest rate (in years)	2
Land loans
Troubled debt restructurings
Period of interest-only monthly payment term loan (in years)	3
Land loans | Minimum
Troubled debt restructurings
Extension of maturity date (in years)	1
Land loans | Maximum
Troubled debt restructurings
Extension of maturity date (in years)	3