Consolidated Businesses - Additional Information (Detail) - USD ($)						3 Months Ended		12 Months Ended
	Jan. 22, 2016	Nov. 25, 2015	Jul. 13, 2015	Jun. 10, 2015	Nov. 03, 2014	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Business Acquisition [Line Items]
Liabilities incurred to be paid in one year	$ 130,000
Impact of subsidiary equity transactions						$ 620,000	$ 626,000
Payments to acquired additional interest in subsidiaries						5,400,000
Actua's share of consolidated business equity transactions						(4,900,000)
Maximum
Business Acquisition [Line Items]
Contingent consideration liability						2,000,000.0
FolioDynamix
Business Acquisition [Line Items]
Cash paid for acquisition					$ 201,699,000
Rolled stock options acquired					$ 4,100,000
FolioDynamix | Scenario, Adjustment
Business Acquisition [Line Items]
Post-closing working capital adjustment							700,000
GovDelivery | Talent Management in Government Inc.
Business Acquisition [Line Items]
Cash paid for acquisition				$ 400,000				$ 100,000
Business acquisition, consideration transferred				500,000
Business combination consideration transferred, liabilities incurred				$ 100,000
GovDelivery | Textizen
Business Acquisition [Line Items]
Cash paid for acquisition			$ 1,200,000
Contingent consideration, asset			$ 400,000
VelocityEHS | WellNet Solutions, Inc. [Member]
Business Acquisition [Line Items]
Cash paid for acquisition		$ 700,000				700,000
Intangible assets recorded in connection with acquisition		1,400,000
Contingent consideration liability		$ 900,000
VelocityEHS | ErgoAdvocate
Business Acquisition [Line Items]
Cash paid for acquisition	1,000,000
Business acquisition, consideration transferred	1,250,000
Liabilities incurred to be paid in six months	$ 130,000
Additional Paid-In Capital
Business Acquisition [Line Items]
Impact of subsidiary equity transactions						$ 492,000	$ 618,000