Debt (Detail) - Borrowings (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Amount outstanding	$ 205,000		$ 200,000
Bank Term Loan [Member]
Amount outstanding	150,000	[1]	180,000	[1]
Contractual annualized interest rate	1.81%	[1]
Revolver [Member]
Amount outstanding	50,000	[1],[2]	20,000	[1],[2]
Contractual annualized interest rate	1.81%	[1],[2]
Other Loan [Member]
Amount outstanding	$ 5,000	[3]		[3]
Contractual annualized interest rate	3.00%	[3]

[1] Both the term and revolver loan rates consisted of a floating Eurodollar base rate of 0.31% plus a margin of 1.5%. However, the Company has an interest rate swap contract which converts the floating Eurodollar base rate to a 2.26% fixed base rate on the first $200.0 million of Company borrowings (see below). As a result, the Company's effective annual interest rate on the $200.0 million of outstanding debt under the 2010 Credit Facility as of December 31, 2012, including the margin, was 3.76%.

[2] The Company had $346.6 million of available borrowing capacity on the revolver (not including the expansion feature) as of December 31, 2012.

[3] In December 2012 the Company borrowed $5.0 million under a previously disclosed financial assistance package provided by an economic development program through the State of Connecticut in connection with the Company's renovation of its Stamford headquarters facility. The loan has a 10 year maturity and bears a 3% fixed rate of interest. Principal payments are deferred for the first five years and the loan may be repaid at any point by the Company without penalty. The loan has a principal forgiveness provision in which up to $2.5 million of the loan may be forgiven if the Company meets certain employment targets in the State of Connecticut during the first five years of the loan.