Goodwill and Intangible Assets - Summary of Activity Related to Goodwill (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2016 USD ($)
Goodwill, Gross [Roll Forward]
Goodwill as of December 31, 2015, Gross Carrying Amount	$ 265,994
Acquisition, Gross Carrying Amount	155
Goodwill as of June 30, 2016, Gross Carrying Amount	266,149
Accumulated Impairment Losses [Roll Forward]
Goodwill as of December 31, 2015, Accumulated Impairment Losses	(39,960)
Goodwill as of June 30, 2016, Accumulated Impairment Losses	(39,960)
Goodwill [Roll Forward]
Goodwill as of December 31, 2015, Net Carrying Amount	226,034
Acquisition, Net of Carrying Amount	155
Goodwill as of June 30, 2016, Net Carrying Amount	$ 226,189