Restructuring (Details) - USD ($)	3 Months Ended					12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2014	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, beginning of period	$ 337,000	$ 1,977,000
Restructuring Reserve, Settled with Cash	(254,000)	(618,000)
Restructuring Reserve, end of period	83,000	1,359,000
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, beginning of period	337,000	1,977,000
Restructuring Reserve, Settled with Cash	(254,000)	(618,000)
Restructuring Reserve, end of period	83,000	$ 1,359,000
Banyan Acquisition and WMT Management Restructuring Plan [Member] | Wealth Management and Trust Segment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost			$ 900,000	$ 1,100,000	$ 700,000	$ 3,700,000
Restructuring and Related Cost, Cost Incurred to Date					$ 6,400,000
Restructuring and Related Cost, Expected Cost Remaining	$ 0