Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Impairment loss		$ 39,700
Goodwill impairment loss			$ 18,900
Available-for-sale Securities Acquired [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Available-for-sale securities acquired	$ 500
PDRI [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Impairment loss		39,700
Goodwill impairment loss		18,900
PDRI [Member] | Customer Relationships [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Intangible asset impairment loss		$ 20,800