Summary of Interest Rate Swap Agreements Designated as Hedge Agreements (Detail) (USD $) In Thousands, unless otherwise specified				9 Months Ended
	Sep. 30, 2014		Dec. 31, 2013	Sep. 30, 2014 Agreement One		Sep. 30, 2014 Agreement Two		Sep. 30, 2014 Agreement Three
Interest Rate Swaps [Line Items]
Nominal Amount	$ 450,000			$ 175,000		$ 175,000		$ 100,000
Effective Date				Dec. 01, 2010		Dec. 01, 2010		Nov. 01, 2011
Pay Rate				1.3975%		1.40%		1.715%
Receive Rate				1-Month LIBOR		1-Month LIBOR		1-Month LIBOR
Expiration Date				Sep. 01, 2015		Sep. 01, 2015		Apr. 01, 2016
Current Liability	5,318	[1]	5,367	1,929	[1]	1,953	[1]	1,436	[1]
Long-Term Liability	520	[2]	3,809					520	[2]
Estimated Total Fair Value at September 30, 2014	$ 5,838			$ 1,929		$ 1,953		$ 1,956

[1] Included in accounts payable and accrued expenses on the condensed consolidated balance sheet as of September 30, 2014.

[2] Included in other long-term liabilities on the condensed consolidated balance sheet as of September 30, 2014.