Acquisitions - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended				0 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Jan. 31, 2014 Subsequent Event [Member]	Aug. 01, 2013 Cable Holdings [Member]	Dec. 31, 2013 Cable Holdings [Member]	Dec. 31, 2013 Ascolta [Member]
Business Acquisition [Line Items]
Cash paid for acquisition, net of cash acquired	$ 7,150	$ 0	$ 0		$ 7,150
Identifiable intangible assets weighted-average life						5 years	5 years
Business acquired Assets and Liabilities				$ 5,186