TRANSACTION AND INTEGRATION RELATED COSTS IN CONNECTION WITH THE COMBINATION - SUMMARY (Details) - USD ($) $ in Thousands		12 Months Ended
	Sep. 29, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition
Stock-based compensation expense		$ 149,230	$ 8,916	$ 7,853
Cost of revenue
Business Acquisition
Stock-based compensation expense		19
Selling and marketing expense
Business Acquisition
Stock-based compensation expense		25,763	863	545
General and administrative expense
Business Acquisition
Stock-based compensation expense		107,662	6,804	6,137
Product development expense
Business Acquisition
Stock-based compensation expense		15,786	$ 1,249	$ 1,171
Angie's List
Business Acquisition
Transaction and integration related costs		44,101
Stock-based compensation expense		122,066
Total		166,167
Charges incurred		44,101
Payments made	$ (1,900)	(35,621)
Accrual as of December 31		8,480
Angie's List | Cost of revenue
Business Acquisition
Transaction and integration related costs		0
Stock-based compensation expense		0
Total		0
Angie's List | Selling and marketing expense
Business Acquisition
Transaction and integration related costs		7,430
Stock-based compensation expense		24,416
Total		31,846
Angie's List | General and administrative expense
Business Acquisition
Transaction and integration related costs		36,120
Stock-based compensation expense		83,420
Total		119,540
Angie's List | Product development expense
Business Acquisition
Transaction and integration related costs		551
Stock-based compensation expense		14,230
Total		$ 14,781