CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
CONDENSED CONSOLIDATED STATEMENTS OF INCOME
Revenue		$ 108,306	$ 102,657
Expenses:
Cost of revenue	[1]	38,285	41,923
Sales and marketing	[1]	7,587	6,559
Research and development	[1]	7,788	5,932
General and administrative	[1]	35,845	36,552
Depreciation and amortization		12,485	8,394
Total operating expenses		101,990	99,360
Income from operations		6,316	3,297
Other income and (expenses):
Realized losses on short-term investments			(4)
Gain on disposal of equipment			534
Interest income		1,338	1,442
Interest expense		(1,413)	(1,259)
Income before taxes		6,241	4,010
Provision for income taxes		2,599	1,645
Net income		3,642	2,365
Net income attributable to common stockholders, basic and diluted		$ 3,569	$ 2,356
Net income per share attributable to common stockholders, basic and diluted:
Basic net income per share (in dollars per share)		$ 0.02	$ 0.02
Diluted net income per share (in dollars per share)		$ 0.02	$ 0.02
Weighted average shares of common stock outstanding:
Basic (in shares)		144,729	151,282
Diluted (in shares)		145,165	152,355

[1] Includes stock-based compensation expense as follows: Three months ended March 31, 2017: Cost of revenue 305; Sales and marketing 390; Research and development 273; General and administrative 2,629; Total stock-based compensation expense 3,597. Three months ended March 31, 2016: Cost of revenue 119; Sales and marketing 154; Research and development 242; General and administrative 1,577; Total stock-based compensation expense 2,092.