Commercial Mortgage Banking - Narrative (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Mortgage Banking [Abstract]
Percentage of controlling interest owned by the company in OMHHF	83.68%
Non-controlling interest	16.32%		16.32%
Number of related party	1
Prepayment costs	$ 4,900	$ 2,600	$ 20,900	$ 4,500
Custodial escrow accounts	309,100		309,100		$ 285,500
Uninsured balance relation to escrow accounts	186,100		186,100
Fair value of servicing rights	43,800		43,800		42,300
Carrying value of loan servicing rights	$ 29,594	$ 29,496	$ 29,594	$ 29,496	$ 30,140	$ 28,879
Servicing rights are amortized using straight-line method	10 years