Segment Reporting and Significant Concentration (Tables)

12 Months Ended

Dec. 31, 2016

Segment Reporting [Abstract]

Summary of Financial Information Relating to Operations by Geographic Region

Financial information relating to our operations by geographic region is as follows (in thousands):

Total Revenues:

	2016		2015		2014
Americas (principally the U.S.)	$	652,376	$	634,389	$	636,482
Europe, Middle East and Africa (principally Europe)		69,425		78,711		79,535
Asia Pacific		39,157		39,420		35,269
Total revenues	$	760,958	$	752,520	$	751,286

Property and Equipment:	As of December 31,
	2016		2015
Americas (principally the U.S.)	$	28,003	$	29,052
Europe, Middle East and Africa (principally Europe)		2,749		3,879
Asia Pacific		2,364		3,061
Total property and equipment	$	33,116	$	35,992

Summary of Revenues from Significant Clients

Revenues from these clients represented the following percentages of our total revenues for the following years:

	2016			2015			2014
Comcast		26	%		24	%		22	%
Charter/Time Warner (combined for all periods)		21	%		21	%		20	%
DISH		13	%		14	%		15	%

Summary of Net Billed Accounts Receivable from Significant Clients

As of December 31, 2016 and 2015, the percentage of net billed accounts receivable balances attributable to these clients were as follows:

	As of December 31,
	2016			2015
Comcast		25	%		30	%
Charter/Time Warner (combined for all periods)		24	%		13	%
DISH		10	%		13	%