Income Taxes - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Contingency [Line Items]
Accumulated earnings of foreign subsidiaries	$ 2,536
Unrecognized tax benefits, impact effective tax rate	817	19
Additions based on uncertain tax positions related to prior periods	813	50
Anticipated release of provision relating to uncertain tax positions due to expiration of certain statutes of limitation in foreign jurisdictions	1,516
Unrecognized Tax Benefits Reductions Resulting from Lapse of Applicable Statute of Limitations Anticipated Duration Period	12 months
Unrecognized tax benefit netted against deferred tax assets	3,104	2,694
Accrued interest and penalty expense related to estimated obligations for unrecognized tax benefits	182	248	239
Liability related to interest and penalties for uncertain tax positions	2,348	3,935
Minimum
Income Tax Contingency [Line Items]
Net operating loss carryforwards, expiration year	2013
Maximum
Income Tax Contingency [Line Items]
Net operating loss carryforwards, expiration year	2032
Foreign Jurisdictions
Income Tax Contingency [Line Items]
Additions based on uncertain tax positions related to prior periods	813
Valuation Allowance Releases
Income Tax Contingency [Line Items]
Valuation allowance movements	562	1,702
Valuation Allowance Other Changes
Income Tax Contingency [Line Items]
Valuation allowance movements	(696)
Release Of Uncertain Tax Positions Related To Interest And Penalties
Income Tax Contingency [Line Items]
Release of provision on uncertain tax positions due to the expiration of certain statutes of limitation in foreign jurisdictions	1,798
Release of uncertain tax positions related to provision
Income Tax Contingency [Line Items]
Release of provision on uncertain tax positions due to the expiration of certain statutes of limitation in foreign jurisdictions	631
United Kingdom
Income Tax Contingency [Line Items]
Non-deductible intercompany bad debt	10,870
Net operating loss carryforwards	49,829
Federal Tax
Income Tax Contingency [Line Items]
Net operating loss carryforwards	86,265
U S State
Income Tax Contingency [Line Items]
Net operating loss carryforwards	78,694
State alternative minimum tax credits	12
Federal Research And Development Credits
Income Tax Contingency [Line Items]
Tax credit carryforward amount	2,839
Tax credit carryforwards, expiration year	2022
California Research And Development Tax Credit
Income Tax Contingency [Line Items]
Tax credit carryforward amount	3,369
Foreign Tax Authority
Income Tax Contingency [Line Items]
Tax credit carryforward amount	$ 6,078
Tax credit carryforwards, expiration year	2017