Segment Information and Revenues - Revenue by Major Service (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Total revenue	$ 560,456	$ 509,557	$ 455,911
Wealth Management
Segment Reporting Information [Line Items]
Total revenue	373,174	348,620	316,546
Wealth Management | Commission [Member]
Segment Reporting Information [Line Items]
Total revenue	164,201	160,241	150,125
Wealth Management | Advisory [Member]
Segment Reporting Information [Line Items]
Total revenue	164,353	145,694	129,417
Wealth Management | Asset-based [Member]
Segment Reporting Information [Line Items]
Total revenue	31,456	26,297	22,653
Wealth Management | Transaction and Fee [Member]
Segment Reporting Information [Line Items]
Total revenue	13,164	16,388	14,351
Tax Preparation
Segment Reporting Information [Line Items]
Total revenue	187,282	160,937	139,365
Tax Preparation | Consumer [Member]
Segment Reporting Information [Line Items]
Total revenue	172,207	147,084	126,289
Tax Preparation | Professional [Member]
Segment Reporting Information [Line Items]
Total revenue	$ 15,075	$ 13,853	$ 13,076