Maximum percentage payroll deduction per employee per quarter.

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- Definition

Percentage of closing market price paid for purchase of common stock shares through employee stock purchase plan.

+ Details

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- Definition

The floor of a customized range of grant date fair values for purposes of disclosing shares potentially issuable under restricted stock awards on all restricted stock plans and other required information pertaining to awards in the customized range.

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- Definition

The ceiling of a customized range of grant date fair values for purposes of disclosing shares potentially issuable under restricted stock awards on all restricted stock plans and other required information pertaining to awards in the customized range.

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- Definition

Number of committed-to-be-released shares held by the Employee Stock Purchase Plan. Committed-to-be-released shares are shares that will be released in the future.

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- Definition

Number of reserved shares held by the Employee Stock Purchase Plan.

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- Definition

The maximum percentage rate stock-based compensation expense is calculated using net of forfeitures estimated from shares granted.

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- Definition

The estimated measure of the percentage of shares, units or grants expected to be forfeited.

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- Definition

Number of shares granted during the period related to Restricted Stock Awards, net of any shares forfeited.

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Grant date fair value of stock related to Restricted Stock Awards granted during the period.

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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 123R
-Paragraph A240
-Subparagraph g(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.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 14.F)
-URI http://asc.fasb.org/extlink&oid=6793087&loc=d3e301413-122809

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
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Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 123R
-Paragraph 64
-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.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Stock Based Compensation (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense related to stock-based compensation	$ 4,555		$ 5,105	$ 9,095	$ 9,976
Omnibus Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense related to stock-based compensation	4,600		5,100	9,100	10,000
Percentage of estimated forfeitures, minimum (in hundredths)				0.00%	0.00%
Percentage of estimated forfeitures, maximum (in hundredths)				10.00%	5.00%
Shares Granted (in shares)		70
Value Per Share, minimum (in dollars per share)		$ 21.41
Value Per Share, maximum (in dollars per share)		$ 23.45
Total Value		$ 1,637
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage payroll deduction that each employee may deduct (in hundredths)				15.00%
Percentage of closing market price paid for purchase of whole shares (in hundredths)				90.00%
Initial number of shares reserved (in shares)	1,000,000			1,000,000
Annual increase in number of shares available for issuance (in shares)	200,000			200,000