Significant Accounting Policies - Additional Information (Detail) (Certain intangible assets [Member], USD $) In Millions, unless otherwise specified	6 Months Ended
Jun. 30, 2014
Certain intangible assets [Member]
Business And Significant Accounting Policies [Line Items]
Estimated useful lives of intangible assets	0 years
Amortization expense	$ 7.2

The aggregate amount of recurring noncash expense charged against earnings in the period to allocate the cost of assets over their estimated remaining economic lives.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Name:	us-gaap_AdjustmentForAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration