Acquisitions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisitions [Abstract]
Goodwill acquired	$ 6,726	$ 2,604
Retirement Plan Services, LLC [Member]
Business Acquisitions [Abstract]
Total consideration paid	13,000
Goodwill acquired	6,700
Contingent consideration, liability	$ 5,100
Downeast Pension Services, Inc.[Member]
Business Acquisitions [Abstract]
Total consideration paid		5,700
Goodwill acquired		2,600
Contingent consideration, liability		$ 1,700
Actuarial Designs & Solutions, Inc. [Member]
Business Acquisitions [Abstract]
Total consideration paid			$ 3,000
Goodwill acquired			1,300
Columbia Ridge Capital Management, Inc. [Member]
Business Acquisitions [Abstract]
Total consideration paid			1,300
Goodwill acquired			$ 800