Changes in Stock Options (Detail) (Stock Options, USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2014
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Outstanding, Beginning balance	1,750		183,208		250
Number of Stock Options, Exercised	(1,500)	[1]	(173,208)	[1]
Number of Stock Options, Forfeited			(21)
Number of Stock Options, Cancelled			(8,229)
Outstanding, Ending balance	250		1,750		250
Weighted Average Base Price, Outstanding, Beginning balance	$ 6.91		$ 6.25		$ 4.30
Weighted Average Fair Value, Exercised	$ 7.34	[1]	$ 6.03	[1]
Weighted Average Base Price, Forfeited			$ 8.41
Weighted Average Base Price, Cancelled			$ 10.62
Weighted Average Base Price, Outstanding, Ending balance	$ 4.30		$ 6.91		$ 4.30
Weighted Average Fair Value, Outstanding, Beginning balance	$ 4.14		$ 4.97		$ 2.47
Weighted Average Fair Value, Exercised	$ 4.42	[1]	$ 4.83	[1]
Weighted Average Fair Value, Forfeited			$ 4.96
Weighted Average Fair Value, Cancelled			$ 8.16
Weighted Average Fair Value, Outstanding, Ending balance	$ 2.47		$ 4.14		$ 2.47

[1] Actua received cash of less than $0.1 million and $1.0 million related to stock options exercised during the years ended December 31, 2013 and 2012.