Represents the cash received on account of intangible assets.

No definition available.

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- Definition

The aggregate amount assigned to a major class of finite-lived intangible assets acquired either individually or as part of a group of assets (in either an asset acquisition or business combination). A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=7658586&loc=d3e16265-109275

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 44

-Subparagraph a(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

+ Details

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- Definition

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

-Subparagraph a(2)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

Reference 2: 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=6943989&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16225-109274

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(2)

-URI http://asc.fasb.org/extlink&oid=7658586&loc=d3e16323-109275

+ Details

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Data Type:	xbrli:monetaryItemType
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- Definition

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=7658586&loc=d3e16323-109275

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

-Subparagraph a(1)

-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.

+ Details

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

+ Details

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- Details

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- Definition

Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

+ Details

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

- Definition

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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Intangible Asset and Goodwill (Details 3) (USD $)	3 Months Ended					3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended			3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended
Intangible Asset and Goodwill (Details 3) (USD $)	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Mar. 31, 2013 Existing technology	Dec. 31, 2012 Existing technology	Mar. 31, 2013 Existing technology Minimum	Dec. 31, 2012 Existing technology Minimum	Mar. 31, 2013 Existing technology Maximum	Dec. 31, 2012 Existing technology Maximum	Mar. 31, 2013 Customer contracts and contractual relationships	Dec. 31, 2012 Customer contracts and contractual relationships	Mar. 31, 2013 Customer contracts and contractual relationships Minimum	Dec. 31, 2012 Customer contracts and contractual relationships Minimum	Mar. 31, 2013 Customer contracts and contractual relationships Maximum	Dec. 31, 2012 Customer contracts and contractual relationships Maximum	Mar. 31, 2013 Non-compete agreements	Dec. 31, 2012 Non-compete agreements	Mar. 31, 2013 Favorable contracts	Mar. 31, 2012 Favorable contracts	Dec. 31, 2012 Favorable contracts
Components of intangible assets
Useful Life (in years)						3 years	3 years	10 years	10 years			1 year	1 year	10 years	10 years	3 years	3 years
Gross Carrying Amount	$ 225,831,000		$ 224,765,000	$ 192,881,000	$ 191,815,000					$ 32,650,000	$ 32,650,000					$ 300,000	$ 300,000
Accumulated Amortization	(79,901,000)		(71,592,000)	(63,466,000)	(57,240,000)					(16,252,000)	(14,194,000)					(183,000)	(158,000)
Net Carrying Amount	145,930,000		153,173,000	129,415,000	134,575,000					16,398,000	18,456,000					117,000	142,000
Cash received related to favorable contracts																		1,400,000	2,400,000
Amortization expense for intangible assets	7,040,000	7,616,000
Acquired intangible assets																		$ 3,400,000		$ 4,800,000