Property and Equipment, Net - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Internally developed software costs capitalized	$ 28,024us-gaap_CapitalizedComputerSoftwareNet	$ 24,901us-gaap_CapitalizedComputerSoftwareNet	$ 32,604us-gaap_CapitalizedComputerSoftwareNet
Depreciation expense	$ 46,019us-gaap_Depreciation	$ 49,922us-gaap_Depreciation	$ 51,926us-gaap_Depreciation

The carrying amount of capitalized computer software costs net of accumulated amortization as of the balance sheet date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 985

-SubTopic 20

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128487-111756

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 985

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756

Name:	us-gaap_CapitalizedComputerSoftwareNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant