CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Revenue		$ 154,187	$ 145,491
Expenses:
Cost of revenue	[1]	41,043	37,203
Sales and marketing	[1]	15,159	13,526
Research and development	[1]	7,104	8,201
General and administrative	[1]	53,883	53,623
Depreciation and amortization		27,934	27,047
Total operating expenses		145,123	139,600
Income from operations		9,064	5,891
Other income and (expenses):
Interest income		290	610
Interest expense		(14,560)	(16,542)
Other expense, net		(22)	(11)
Loss before taxes		(5,228)	(10,052)
Benefit from income taxes		(3,545)	(1,729)
Net loss		(1,683)	(8,323)
Net loss attributable to common stockholders, basic and diluted		$ (1,683)	$ (8,323)
Net loss per share attributable to common stockholders, basic and diluted:
Basic net (loss) income per share (in dollars per share)		$ (0.01)	$ (0.06)
Diluted net (loss) income per share (in dollars per share)		$ (0.01)	$ (0.06)
Weighted average shares of common stock outstanding:
Basic (in shares)		149,183	147,774
Diluted (in shares)		149,183	147,774

[1] (1) Includes stock-based compensation expense as follows:      
  Cost of revenue $ 165
  $ 77
  Sales and marketing 620
  300
  Research and development 453
  370
  General and administrative 6,018
  4,492
  Total stock-based compensation expense $ 7,256
  $ 5,239