Commitments and Financial Instruments with Off-Balance-Sheet Risk - Changes in Allowance for Indemnifications Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Change in the allowance for indemnification losses
Provision for indemnification			$ 243	$ 212
Indemnification reserve for recourse provisions
Change in the allowance for indemnification losses
Allowance, beginning of period	$ 2,503	$ 2,227	2,363	2,089
Provision for indemnification	103	73	243	212
Payments	(350)		(350)	(1)
Allowance, end of period	$ 2,256	$ 2,300	$ 2,256	$ 2,300