Debt and Short-Term Borrowings - Total Debt (Detail) - USD ($) $ in Thousands		Jun. 30, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Note payable		$ 5,000
Total debt		666,197	$ 693,912
Term A due on April 17, 2018 [Member] | Senior Secured Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility	[1],[2]	269,781	277,239
Term B due on April 17, 2020 [Member] | Senior Secured Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility	[2],[3]	387,749	389,340
Expiring on April 17, 2018 [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility		4,000	23,000
Note Payable due on October 1, 2017 [Member]
Debt Instrument [Line Items]
Note payable	[2]	3,638	$ 4,333
Note Payable due on July 1, 2017 [Member]
Debt Instrument [Line Items]
Note payable	[2]	$ 1,029

[1] Applicable margin of 2.50% at June 30, 2015 and December 31, 2014.

[2] Includes unamortized discount.

[3] Subject to a minimum rate ("LIBOR floor") of 0.75% plus applicable margin of 2.75% at June 30, 2015 and December 31, 2014.