Debt Trust preferred debt instruments (Details)				12 Months Ended
	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Jul. 14, 2005 CAD	Dec. 31, 2013 Connecticut Statutory Trust I [Member] USD ($)	Dec. 31, 2013 Connecticut Statutory Trust II [Member] USD ($)	Dec. 31, 2013 Connecticut Statutory Trust III [Member] USD ($)	Dec. 31, 2013 Delaware Statutory Trust III [Member] USD ($)	Dec. 31, 2013 Delaware Statutory Trust IV [Member] USD ($)	Dec. 31, 2013 Delaware Statutory Trust VI [Member] USD ($)
Debt Instrument [Line Items]
LROC preferred units, at fair value	$ 14,854,000	$ 13,655,000	78,000,000	$ 15,000	$ 17,500	$ 20,000	$ 15,000	$ 10,000	$ 13,000
Issue date of trust				Dec. 04, 2002	May 15, 2003	Oct. 29, 2003	May 23, 2003	Sep. 30, 2003	Jan. 08, 2004
Redemption date				Dec. 04, 2032	May 15, 2033	Oct. 29, 2033	May 23, 2033	Sep. 30, 2033	Jan. 08, 2034