Segment Reporting and Significant Concentration (Tables)

12 Months Ended

Dec. 31, 2014

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:

	2014		2013		2012
Americas (principally the U.S.)	$	636,482	$	633,163	$	652,008
Europe, Middle East and Africa (principally Europe)		79,535		80,527		73,113
Asia Pacific		35,269		33,778		31,745
Total revenues	$	751,286	$	747,468	$	756,866

Property and Equipment:	As of December 31,
	2014		2013
Americas (principally the U.S.)	$	31,912	$	27,115
Europe, Middle East and Africa		3,618		4,280
Asia Pacific		2,796		3,666
Total property and equipment	$	38,326	$	35,061

Summary of Revenues from Significant Clients

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

	2014			2013			2012
Comcast		22	%		19	%		20	%
DISH		15	%		15	%		14	%
Time Warner		11	%		11	%		10	%

Summary of Net Billed Accounts Receivable from Significant Clients

As of December 31, 2014 and 2013, the percentage of net billed accounts receivable balances attributable to these clients were as follows:

	As of December 31,
	2014			2013
Comcast		21	%		21	%
DISH		13	%		14	%
Time Warner		12	%		9	%