Other Investments (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
FHLB and FRB Stock
Investment in FRB and FHLB stock	$ 58,400,000		$ 58,400,000		$ 64,400,000
Private Equity and Alternative Investments
Investments carried at cost	29,700,000		29,700,000		34,000,000
Recognized impairment losses on cost method investments	0	0	0	400,000
Private equity and venture capital
Private Equity and Alternative Investments
Investments carried at cost	18,411,000		18,411,000		20,298,000
Real estate
Private Equity and Alternative Investments
Investments carried at cost	7,623,000		7,623,000		7,646,000
Hedge
Private Equity and Alternative Investments
Investments carried at cost	1,733,000		1,733,000		2,733,000
Other
Private Equity and Alternative Investments
Investments carried at cost	$ 1,981,000		$ 1,981,000		$ 3,275,000