Borrowings (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012		Dec. 31, 2011
Debt Instrument [Line Items]
Amount outstanding	$ 240,293		$ 200,000
Term Loan
Debt Instrument [Line Items]
Amount outstanding	172,500		180,000
Contractual annualized interest rate	1.97%	[1]
Revolver
Debt Instrument [Line Items]
Amount outstanding	$ 67,793	[2],[3]	$ 20,000	[2],[3]
Revolver | Minimum
Debt Instrument [Line Items]
Contractual annualized interest rate	1.74%	[1],[2],[3]
Revolver | Maximum
Debt Instrument [Line Items]
Contractual annualized interest rate	1.97%	[1],[2],[3]

[1] The term loan rate consisted of a 0.47% floating Eurodollar base rate plus a margin of 1.50%. The Eurodollar base rates on the revolver ranged from 0.24% to 0.47%, plus a margin of 1.50%. However, the Company has an interest rate swap contract which converts the floating Eurodollar base rates to a fixed base rate on $200.0 million of borrowings (see below). As a result, the Company's effective annual interest rate on its total debt outstanding as of March 31, 2012 was 3.43%.

[2] The $67.8 million outstanding as of March 31, 2012 includes $67.5 million borrowed under the 2010 Credit Agreement and $0.3 million that was borrowed under a separate, short-term lending arrangement.

[3] The Company had $329.3 million of available borrowing capacity on the revolver (not including the expansion feature) as of March 31, 2012.