Segment Information and Revenues - Information on Reportable Segments (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) Segment	Mar. 31, 2019 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | Segment	2
Revenue:
Revenues	$ 263,320	$ 225,768
Operating income:
Total operating income (loss)	(241,839)	70,113
Other loss, net	(6,135)	(3,958)
Income tax expense	(67,520)	(3,985)
Net income (loss) attributable to Blucora, Inc.	(315,494)	62,170
Corporate-level activity
Operating income:
Total operating income (loss)	(302,190)	(20,699)
Segment Reconciling Items
Operating income:
Other loss, net	(6,135)	(3,958)
Income tax expense	(67,520)	(3,985)
Wealth Management
Revenue:
Revenues	144,989	89,532
Wealth Management | Commission revenue
Revenue:
Revenues	50,580	37,160
Wealth Management | Advisory revenue
Revenue:
Revenues	78,757	39,757
Wealth Management | Asset-based revenue
Revenue:
Revenues	10,579	9,693
Wealth Management | Transaction and fee revenue
Revenue:
Revenues	5,073	2,922
Wealth Management | Operating Segments
Revenue:
Revenues	144,989	89,532
Operating income:
Total operating income (loss)	22,598	11,540
Tax Preparation
Revenue:
Revenues	118,331	136,236
Tax Preparation | Consumer
Revenue:
Revenues	103,821	123,942
Tax Preparation | Professional
Revenue:
Revenues	14,510	12,294
Tax Preparation | Operating Segments
Revenue:
Revenues	118,331	136,236
Operating income:
Total operating income (loss)	$ 37,753	$ 79,272