Subordinated Note And Junior Subordinated Note (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2011 securities years	Dec. 31, 2010	Dec. 31, 2007	Sep. 29, 2006 years	Dec. 31, 2003
Subordinated Note And Junior Subordinated Note [Abstract]
Subordinated note				$ 50.0
Subordinated note original maturity term, years				10
Subordinated note interest rate determining factor prior to January 1, 2011				three-month LIBOR plus 110 basis points
Subordinated note extension	LIBOR plus 110 basis points
Change in subordinated note interest rate through December 31, 2012 at extension	LIBOR plus 330 basis points
Current interest rate on subordinated note	3.67%	1.40%
Number of trusts established for special purpose	5		2		3
Junior subordinated notes original maturity term, years	30
Junior subordinated notes	$ 121.1	$ 121.1
Junior subordinated note, weighted average interest rate	2.51%	2.46%