Investments is Low Income Housing Tax Credits Investments in Qualified Affordable Housing Projects (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Investments in Affordable Housing Projects [Abstract]
Original investment value	$ 47,627	$ 47,379
Amortization Method Qualified Affordable Housing Project Investments	36,868	39,606
Capital commitment relating to low income housing project investments	7,696	12,161
Tax credits and benefits	5,705	5,366
Amortization of investments	3,988	3,725
Net income tax benefit	$ 1,718	$ 1,641