Acquisitions - Additional Information (Detail) $ in Thousands, € in Millions				3 Months Ended		9 Months Ended		12 Months Ended
	Nov. 04, 2015 USD ($)	Nov. 04, 2015 EUR (€)	Aug. 12, 2014 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)
Business Acquisition [Line Items]
Additional borrowing						$ 112,000	$ 149,500
Business acquisition cash paid			$ 205,100
Acquisition related transaction expenses								$ 2,700
Operating Income (loss)				$ 23,886	$ 31,869	53,975	58,901
Subsequent Event
Business Acquisition [Line Items]
Business combination, cash and stock consideration	$ 200,000	€ 180
Percentage of ownership interest acquired	100.00%	100.00%
Revolving Credit Facility
Business Acquisition [Line Items]
Additional borrowing			60,500
Revolving Credit Facility | Subsequent Event
Business Acquisition [Line Items]
Additional borrowing	$ 181,500
Term Credit Facility [Member]
Business Acquisition [Line Items]
Additional borrowing			$ 150,000
Retail Decisions [Member]
Business Acquisition [Line Items]
Revenue				10,200	5,800	30,300	5,800
Operating Income (loss)				$ (1,800)	$ 100	$ (5,600)	$ 100