Goodwill and Intangible Assets - Schedule of Changes in the Carrying Amount of Goodwill (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2015 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill gross, Beginning Balance	$ 163,755
Goodwill gross, Additions	600
Goodwill gross, Impairments	0
Goodwill gross, Ending Balance	164,355
Accumulated impairment losses, Beginning Balance	(38,240)
Accumulated impairment losses, Additions	0
Accumulated impairment losses, Impairments	0
Accumulated impairment losses, Ending Balance	(38,240)
Goodwill Net, Beginning balance	125,515
Goodwill Net, Additions	600
Goodwill Net, Impairments	0
Goodwill Net, Ending balance	$ 126,115