Goodwill and Intangibles, net - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended		3 Months Ended				6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 Bolt	Mar. 31, 2013 Bolt	Jun. 30, 2013 Subsidiaries	Jun. 30, 2012 Subsidiaries	Jun. 30, 2013 Subsidiaries	Jun. 30, 2012 Subsidiaries
Goodwill And Intangible Assets [Line Items]
Amortization of intangible assets	$ 1,926,000	$ 1,436,000	$ 4,825,000	$ 1,860,000	$ 100,000	$ 1,000,000	$ 1,900,000	$ 1,400,000	$ 4,800,000	$ 1,900,000
Goodwill increased amount			12,100,000
Decrease in intangible assets			$ (11,000,000)