Restructuring and Related Reorganization Charges - Additional Information (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Restructuring and Related Activities [Abstract]
Restructuring and related reorganization charges	[1]	$ 9,708	$ 9,833	$ 11,607	$ 39,636
Total expected restructuring charges in current year		10,000		10,000
Accrued restructuring liability		$ 17,000		$ 17,000		$ 18,000

[1] Includes stock-based compensation as follows: Cost of revenue $2,727 thousand, $2,884 thousand, $5,566 thousand, and $5,292 thousand; Selling and marketing $10,363 thousand, $25,454 thousand, $21,094 thousand, and $32,496 thousand; Technology and content $14,599 thousand, $28,820 thousand, $27,637 thousand, and $39,441 thousand; General and administrative $22,413 thousand, $42,803 thousand, $43,016 thousand, and $60,467 thousand; Restructuring and related reorganization charges $0 thousand, $470 thousand, $0 thousand, and $11,643 thousand