TRANSACTION AND INTEGRATION RELATED COSTS IN CONNECTION WITH THE COMBINATION - Summary (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Business Acquisition
Stock-based compensation expense	$ 24,906	$ 4,461
Cost of revenue
Business Acquisition
Stock-based compensation expense	1	2
Selling and marketing expense
Business Acquisition
Stock-based compensation expense	661	498
General and administrative expense
Business Acquisition
Stock-based compensation expense	21,693	3,616
Product development expense
Business Acquisition
Stock-based compensation expense	2,551	$ 345
Angie's List
Business Acquisition
Integration related costs	2,504
Stock-based compensation expense	19,106
Total	21,610
Accrual as of January 1	8,480
Charges incurred	2,504
Payments made	(8,214)
Accrual as of March 31	2,770
Angie's List | Cost of revenue
Business Acquisition
Integration related costs	0
Stock-based compensation expense	0
Total	0
Angie's List | Selling and marketing expense
Business Acquisition
Integration related costs	0
Stock-based compensation expense	410
Total	410
Angie's List | General and administrative expense
Business Acquisition
Integration related costs	2,504
Stock-based compensation expense	16,704
Total	19,208
Angie's List | Product development expense
Business Acquisition
Integration related costs	0
Stock-based compensation expense	1,992
Total	$ 1,992