Shareholders' Equity Shareholders' Equity (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
Jun. 30, 2014
Stockholders' Equity Note [Abstract]
Common stock and additional paid-in capital, beginning of period	$ 42,955
Income tax benefit of common stock options exercised	6,966
Common stock issued pursuant to stock-based compensation plans, net	20,356
Stock-based compensation expense	17,163
Repurchase of common stock	(43,003)
Common stock and additional paid-in capital, end of period	$ 44,437

This element represents the amount of recognized equity-based compensation during the period, that is, the amount recognized as expense in the income statement (or as asset if compensation is capitalized). Alternate captions include the words "stock-based compensation".

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 35

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6415241&loc=d3e4534-113899

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

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-Name Accounting Standards Codification

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-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 20

-Section 55

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- Definition

Amount of increase in additional paid in capital (APIC) resulting from a tax benefit associated with share-based compensation plan other than an employee stock ownership plan (ESOP). Includes, but is not limited to, excess tax benefit.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

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-Paragraph 2

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

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-Publisher FASB

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-SubTopic 740

-Section 45

-Paragraph 2

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- Definition

Amount of par value plus amounts in excess of par value or issuance value for common stock held by shareholders. Includes common stock repurchased and held as treasury stock.

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- Definition

Value of stock (or other type of equity) issued during the period as a result of any equity-based compensation plan other than an employee stock ownership plan (ESOP), net of stock value of such awards forfeited. Stock issued could result from the issuance of restricted stock, the exercise of stock options, stock issued under employee stock purchase plans, and/or other employee benefit plans.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

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-Section 50

-Paragraph 2

-Subparagraph (d)(1)

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 29, 30, 31

-Article 5

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- Definition

Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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