Fair Value Measurements (Fair Value Measurements Summary of Assets Carried at Fair Value Measured on Nonrecurring Basis) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended	12 Months Ended
Dec. 31, 2011	Dec. 31, 2011	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011
Fair Value Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Finite-lived intangible assets	$ 4,596	$ 4,596	$ 4,226	$ 4,596	$ 21,564
Finite-lived intangible assets, Total Losses	(14,800)	14,830	(14,830)	(14,800)
Significant unobservable inputs (Level 3)
Fair Value Assets And Liabilities Measured On Nonrecurring Basis [Line Items]
Finite-lived intangible assets	$ 4,596	$ 4,596		$ 4,596

The amount of impairment loss recognized in the period resulting from the write-down of the carrying amount of a finite-lived intangible asset to fair value.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 3

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7658586&loc=d3e16373-109275

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 46

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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