CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Revenue		$ 92,755	$ 108,306
Expenses:
Cost of revenue	[1]	33,491	38,285
Sales and marketing	[1]	7,902	7,587
Research and development	[1]	6,421	7,788
General and administrative	[1]	49,396	35,845
Depreciation and amortization		16,380	12,485
Total operating expenses		113,590	101,990
(Loss) Income from operations		(20,835)	6,316
Other income and (expenses):
Realized losses on short-term investments		(1,035)	0
Loss on disposal of equipment		(85)	0
Interest income		1,395	1,338
Interest expense		(1,882)	(1,413)
(Loss) Income before taxes		(22,442)	6,241
(Benefit from) Provision for income taxes		(5,608)	2,599
Net (loss) income		(16,834)	3,642
Net (loss) income attributable to common stockholders, basic and diluted		$ (16,272)	$ 3,569
Net (loss) income per share attributable to common stockholders, basic and diluted:
Basic net (loss) income per share (in dollars per share)		$ (0.12)	$ 0.02
Diluted net (loss) income per share (in dollars per share)		$ (0.12)	$ 0.02
Weighted average shares of common stock outstanding:
Basic (in shares)		139,378	144,729
Diluted (in shares)		139,378	145,165

[1] (1)Includes stock-based compensation expense as follows: Cost of revenue$140 $305 Sales and marketing469 390 Research and development628 273 General and administrative2,511 2,629 Total stock-based compensation expense$3,748 $3,597