Investments (Details 15) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Financing Receivable Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	$ 57,541		$ 61,812
Impaired Financing Receivable Recorded Investment	56,855		60,904
Impaired Financing Receivable Related Allowance	9,884		8,188
Impaired Financing Receivable Net Of Related Allowance	46,971		52,716
Impaired Financing Receivable, Average Recorded Investment	58,879	36,492
Impaired Financing Receivable Interest Income Accrual Method	477	285
Commercial Real Estate Other Receivable With No Related Allowance [Member]
Financing Receivable Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	12,189		32,088
Impaired Financing Receivable Recorded Investment	11,646		31,496
Impaired Financing Receivable Related Allowance	0		0
Impaired Financing Receivable Net Of Related Allowance	11,646		31,496
Impaired Financing Receivable, Average Recorded Investment	21,571	17,751
Impaired Financing Receivable Interest Income Accrual Method	169	167
Commercial Real Estate Other Receivable With Related Allowance [Member]
Financing Receivable Impaired [Line Items]
Impaired Financing Receivable, Unpaid Principal Balance	45,352		29,724
Impaired Financing Receivable Recorded Investment	45,209		29,408
Impaired Financing Receivable Related Allowance	9,884		8,188
Impaired Financing Receivable Net Of Related Allowance	35,325		21,220
Impaired Financing Receivable, Average Recorded Investment	37,308	18,741
Impaired Financing Receivable Interest Income Accrual Method	$ 308	$ 118