Benefit Plans (Details 3) (USD $) In Thousands, except Per Share data, unless otherwise specified	6 Months Ended
Jul. 01, 2011	Dec. 31, 2010
Stock options outstanding
Stock Options Outstanding, Number Outstanding at July 1, 2011	9,248	11,020
Stock Option Outstanding, Weighted-Average Remaining Contractual Life	4.0
Stock Option Outstanding, Weighted Average Exercise Price	$ 7.12	$ 6.90
Stock Options Exercisable, Number Exercisable at July 1, 2011	6,492
Stock Options Exercisable, Weighted Average Exercise Price	$ 7.31
Exercise Price Range One [Member]
Stock options outstanding
Range of Exercise Prices, Lower Limit	$ 0.19
Range of Exercise Prices, Upper Limit	$ 5.14
Stock Options Outstanding, Number Outstanding at July 1, 2011	1,467
Stock Option Outstanding, Weighted-Average Remaining Contractual Life	5.9
Stock Option Outstanding, Weighted Average Exercise Price	$ 2.77
Stock Options Exercisable, Number Exercisable at July 1, 2011	866
Stock Options Exercisable, Weighted Average Exercise Price	$ 3.12
Exercise Price Range Two [Member]
Stock options outstanding
Range of Exercise Prices, Lower Limit	$ 5.18
Range of Exercise Prices, Upper Limit	$ 5.87
Stock Options Outstanding, Number Outstanding at July 1, 2011	1,483
Stock Option Outstanding, Weighted-Average Remaining Contractual Life	3.6
Stock Option Outstanding, Weighted Average Exercise Price	$ 5.76
Stock Options Exercisable, Number Exercisable at July 1, 2011	1,097
Stock Options Exercisable, Weighted Average Exercise Price	$ 5.79
Exercise Price Range Three [Member]
Stock options outstanding
Range of Exercise Prices, Lower Limit	$ 5.88
Range of Exercise Prices, Upper Limit	$ 8.12
Stock Options Outstanding, Number Outstanding at July 1, 2011	1,036
Stock Option Outstanding, Weighted-Average Remaining Contractual Life	4.8
Stock Option Outstanding, Weighted Average Exercise Price	$ 6.65
Stock Options Exercisable, Number Exercisable at July 1, 2011	509
Stock Options Exercisable, Weighted Average Exercise Price	$ 6.72
Exercise Price Range Four [Member]
Stock options outstanding
Range of Exercise Prices, Lower Limit	$ 8.17
Range of Exercise Prices, Upper Limit	$ 8.17
Stock Options Outstanding, Number Outstanding at July 1, 2011	1,895
Stock Option Outstanding, Weighted-Average Remaining Contractual Life	3.7
Stock Option Outstanding, Weighted Average Exercise Price	$ 8.17
Stock Options Exercisable, Number Exercisable at July 1, 2011	1,523
Stock Options Exercisable, Weighted Average Exercise Price	$ 8.17
Exercise Price Range Five [Member]
Stock options outstanding
Range of Exercise Prices, Lower Limit	$ 8.20
Range of Exercise Prices, Upper Limit	$ 8.65
Stock Options Outstanding, Number Outstanding at July 1, 2011	1,332
Stock Option Outstanding, Weighted-Average Remaining Contractual Life	2.7
Stock Option Outstanding, Weighted Average Exercise Price	$ 8.25
Stock Options Exercisable, Number Exercisable at July 1, 2011	1,313
Stock Options Exercisable, Weighted Average Exercise Price	$ 8.25
Exercise Price Range Six [Member]
Stock options outstanding
Range of Exercise Prices, Lower Limit	$ 8.69
Range of Exercise Prices, Upper Limit	$ 9.69
Stock Options Outstanding, Number Outstanding at July 1, 2011	1,398
Stock Option Outstanding, Weighted-Average Remaining Contractual Life	5.0
Stock Option Outstanding, Weighted Average Exercise Price	$ 9.39
Stock Options Exercisable, Number Exercisable at July 1, 2011	555
Stock Options Exercisable, Weighted Average Exercise Price	$ 9.04
Exercise Price Range Seven [Member]
Stock options outstanding
Range of Exercise Prices, Lower Limit	$ 9.74
Range of Exercise Prices, Upper Limit	$ 16.73
Stock Options Outstanding, Number Outstanding at July 1, 2011	637
Stock Option Outstanding, Weighted-Average Remaining Contractual Life	1.2
Stock Option Outstanding, Weighted Average Exercise Price	$ 10.63
Stock Options Exercisable, Number Exercisable at July 1, 2011	629
Stock Options Exercisable, Weighted Average Exercise Price	$ 10.63

Summarized information regarding stock options outstanding.

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- Definition

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 123R
-Paragraph A240
-Subparagraph b(1)(c), d(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 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 123R
-Paragraph A240
-Subparagraph b(1)(c)
-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 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding as of the balance sheet date, including vested options.

+ References

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

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 123R
-Paragraph A240
-Subparagraph b(1)(a)
-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 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 123R
-Paragraph A240
-Subparagraph b(1)(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.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The weighted average price as of the beginning of the year at which grantees can acquire the shares reserved for issuance under the stock option plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 123R
-Paragraph A240
-Subparagraph b(1)(a)
-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 718
-SubTopic 10
-Section 50
-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The weighted-average period between the balance sheet date and expiration date for fully vested and expected to vest options outstanding, which may be expressed in a decimal value for number of years.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 123R
-Paragraph A240
-Subparagraph d(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 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (e)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 123R
-Paragraph 64
-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 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (g)
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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

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