Financial Instruments (Details 3) (USD $) In Thousands, unless otherwise specified						9 Months Ended				9 Months Ended				9 Months Ended						9 Months Ended
	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2012 Level 3	Dec. 31, 2011 Level 3	Sep. 30, 2012 Non-Agency Residential Mortgage Backed Securities Level 3 Discounted cash flow	Sep. 30, 2012 Non-Agency Residential Mortgage Backed Securities Level 3 Discounted cash flow Minimum	Sep. 30, 2012 Non-Agency Residential Mortgage Backed Securities Level 3 Discounted cash flow Maximum	Sep. 30, 2012 Non-Agency Residential Mortgage Backed Securities Level 3 Discounted cash flow Weighted average	Sep. 30, 2012 Commercial mortgage-backed securities Level 3 Comparable market data	Sep. 30, 2012 Commercial mortgage-backed securities Level 3 Comparable market data Minimum	Sep. 30, 2012 Commercial mortgage-backed securities Level 3 Comparable market data Maximum	Sep. 30, 2012 Commercial mortgage-backed securities Level 3 Comparable market data Weighted average	Sep. 30, 2012 Other debt obligations Level 3 Discounted cash flow	Sep. 30, 2012 Other debt obligations Level 3 Discounted cash flow Minimum	Sep. 30, 2012 Other debt obligations Level 3 Discounted cash flow Maximum	Sep. 30, 2012 Other debt obligations Level 3 Discounted cash flow Weighted average	Sep. 30, 2012 Interest Rate Lock Commitments Level 3	Sep. 30, 2012 Investments Level 3	Dec. 31, 2011 Investments Level 3	Sep. 30, 2012 Investments Level 3 Market comparable companies Minimum	Sep. 30, 2012 Investments Level 3 Market comparable companies Maximum	Sep. 30, 2012 Investments Level 3 Market comparable companies Weighted average	Sep. 30, 2012 Investments Level 3 Discounted future exit value	Sep. 30, 2012 Investment in FATV	Dec. 31, 2011 Investment in FATV	Sep. 30, 2012 Investment in FATV Level 3
Disclosure About Significant Unobservable Inputs
Investments	$ 19,253	$ 18,310																$ 19,253	$ 18,310					$ 16,015	$ 15,863	$ 16,000
Unobservable Input
Default rate (as a percent)						6.00%	18.00%	9.80%						0.00%	0.50%	0.40%
Prepayment rate (as a percent)						0.50%	15.00%	6.30%						1.20%	15.00%	2.90%
Loss severity (as a percent)						50.00%	65.00%	55.50%						0.00%	25.00%	22.20%
Discount rate (as a percent)						5.40%	8.60%	6.80%						0.60%	1.90%	0.60%				0.00%	45.00%	23.00%	0.00%
Estimated rate of closure (as a percent)																	71.00%
Fair Value			$ 48,450	$ 80,198	$ 11,281				$ 3,819				$ 10,487
Spread over benchmark (as a percent)										3.00%	13.00%	9.00%
Enterprise value/Revenue multiple (as a percent)																				1.5	7.2	5.9