Nature of Business (Details) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
	Apr. 01, 2014 USD ($) item	Jun. 30, 2015 USD ($) $ / shares shares	Jun. 30, 2014 USD ($) $ / shares shares	Jun. 30, 2015 USD ($) segment $ / shares shares	Jun. 30, 2014 USD ($) $ / shares shares	Dec. 31, 2014 $ / shares
Nature of business
Number of operating segments | segment				1
Nature of Business
Assets acquired in cash | $					$ 101,891
Numerator for earnings (loss) per common share calculation:
Net income (loss) | $		$ 3,431	$ 5,318	$ 5,894	$ 5,566
Denominator for earnings per common share calculation:
Weighted-average common shares, basic		42,737	42,345	42,566	42,259
Effect of dilutive securities:
Stock options and restricted stock		553	173	701	248
Weighted-average common shares, diluted		43,290	42,518	43,267	42,507
EPS
Basic (in dollars per share) | $ / shares		$ 0.08	$ 0.13	$ 0.14	$ 0.13
Diluted (in dollars per share) | $ / shares		$ 0.08	$ 0.13	$ 0.14	$ 0.13
Shares excluded from the computation of diluted income (loss) per common share		1,000		1,000
Common Class A
EPS
Par value of common stock (in dollars per share) | $ / shares		$ 0.0001		$ 0.0001		$ 0.0001
Common Class B
EPS
Par value of common stock (in dollars per share) | $ / shares		$ 0.0001		$ 0.0001		$ 0.0001
Cable Networks Acquisition
Nature of Business
Number of Spanish-language cable television networks whose assets are acquired | item	3
Assets acquired in cash | $	$ 101,900