Income Taxes (Summary of Deferred Tax Assets and Liabilities) (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Income Taxes [Line Items]
Accounts receivable, principally due to the allowance for doubtful accounts	$ 4,028	$ 3,251
Accrued expenses not currently deductible for tax	2,257	2,995
Stock based compensation	8,226	8,289
Foreign tax credit	177	177
Net operating loss carry forwards	4,291	3,168
Fixed assets	580
Other	643	363
Deferred tax assets before valuation allowance	20,202	18,243
Valuation allowance	(1,382)	(1,709)
Deferred tax assets, net	18,820	16,534
Property and equipment, principally due to differences between book and tax depreciation		(4,020)
Intangibles-including goodwill	(165,270)	(139,126)
Basis difference in investment in foreign subsidiaries	(26,926)
Other	(769)
Deferred tax liabilities	(192,965)	(143,146)
Net deferred tax liabilities	$ (174,145)	$ (126,612)