Income Taxes (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Deferred tax assets
Accounts receivable allowances	$ 654	$ 800
Unearned revenue		873
Accrued liabilities not yet deductible	4,515	3,436
Federal and State net operating loss ("NOL") carryforwards	37,252	45,483
Tax credit carryforwards	833	167
Stock-based compensation	4,221	1,971
Other	1,355	1,109
Total deferred tax assets	48,830	53,839
Less valuation allowance	(27,897)	(667)
Deferred tax assets after valuation allowance	20,933	53,172
Deferred tax liabilities:
Purchased intangibles	(37,658)	(44,548)
Property and equipment	(9,014)	(11,680)
Other	(1,291)	(1,625)
Total deferred tax liabilities	(47,963)	(57,853)
Net deferred tax liabilities	(27,030)	(4,681)
Deferred tax assets:
Current	864	4,796
Noncurrent	171
Deferred tax liabilities:
Current	(37)
Noncurrent	(28,028)	(9,477)
Net deferred tax liabilities	$ (27,030)	$ (4,681)