Other Assets (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Line Items]
Security deposits	$ 6,581		$ 3,959
Debt issuance costs	3,866		4,987
Benefit plan-related assets	38,403		36,089
Non-current deferred tax assets	22,795		21,166
Tenant improvement allowance	16,062	[1]	24,570	[1]
Other	2,638		2,322
Total other assets	$ 90,345		$ 93,093

[1] Includes contractual amounts receivable related to the renovation of the Company's Stamford headquarters facility (see Property, equipment and leasehold improvements in Note 1 - Business and Significant Accounting Policies for additional description).