Stock Compensation Plans (SSAR's And Stock Option Exercisable) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2011
$26 - $30 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price Range, lower limit	$ 26
Price Range, upper limit	$ 30
$31 - $35 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price Range, lower limit	$ 31
Price Range, upper limit	$ 35
$36 - $40 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price Range, lower limit	$ 36
Price Range, upper limit	$ 40
$41 - $50 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price Range, lower limit	$ 41
Price Range, upper limit	$ 50
$51 - $55 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price Range, lower limit	$ 51
Price Range, upper limit	$ 55
SSAR's And Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number Exercisable	627
Weighted Average Exercise Price	$ 36.86
Aggregate Intrinsic Value	$ 9,760
SSAR's And Stock Options [Member] \| $26 - $30 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number Exercisable	131
Weighted Average Remaining Contractual Life (in years)	1.1
Weighted Average Exercise Price	$ 29.73
SSAR's And Stock Options [Member] \| $31 - $35 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number Exercisable	224
Weighted Average Remaining Contractual Life (in years)	1.2
Weighted Average Exercise Price	$ 33.05
SSAR's And Stock Options [Member] \| $36 - $40 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number Exercisable	65
Weighted Average Remaining Contractual Life (in years)	2.6
Weighted Average Exercise Price	$ 37.27
SSAR's And Stock Options [Member] \| $41 - $50 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number Exercisable	136
Weighted Average Remaining Contractual Life (in years)	3.3
Weighted Average Exercise Price	$ 42.18
SSAR's And Stock Options [Member] \| $51 - $55 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number Exercisable	71
Weighted Average Remaining Contractual Life (in years)	4.7
Weighted Average Exercise Price	$ 51.44

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The total dollar difference between fair values of the underlying shares reserved for issuance and exercise prices of vested portions of options outstanding and currently exercisable under the option plan as of the balance sheet date.

+ References

Reference 1: 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

Weighted average exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding.

+ 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)(iii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

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- Definition

The weighted average remaining life of the exercisable stock options as of the balance sheet date for all option plans in the customized range of exercise prices.

+ 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 (e)(2)

-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)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The number of shares reserved for issuance pertaining to the outstanding exercisable stock options as of the balance sheet date in the customized range of exercise prices for which the market and performance vesting condition has been satisfied.

+ 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)(iii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

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- Definition

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

+ Details

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