v2.4.0.6

Stockholders' Equity (Nonvested Stock Awards) (Detail) (USD $)	3 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested Stock Awards, Beginning balance (in shares)		1,804,514
Nonvested Stock Awards, Shares Granted (in shares)		2,067,191
Nonvested Stock Awards, Shares Vested (in shares)	(258,952)	(1,015,681)
Nonvested Stock Awards, Shares Forfeited (in shares)		(431,584)
Nonvested Stock Awards Shares, Ending balance (in shares)	2,424,440	2,424,440
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Weighted Average Grant-Date Fair Value, Beginning balance (in dollars per share)		$ 19.75
Weighted Average Grant-Date Fair Value, Granted (in dollars per share)		$ 21.17
Weighted Average Grant-Date Fair Value, Vested (in dollars per share)		$ 18.91
Weighted Average Grant-Date Fair Value, Forfeited (in dollars per share)		$ 21.58
Weighted Average Grant-Date Fair Value, Ending balance (in dollars per share)	$ 20.99	$ 20.99
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested Stock Awards, Beginning balance (in shares)		1,385,420
Nonvested Stock Awards, Shares Granted (in shares)		1,649,814
Nonvested Stock Awards, Shares Vested (in shares)		(864,040)
Nonvested Stock Awards, Shares Forfeited (in shares)		(204,495)
Nonvested Stock Awards Shares, Ending balance (in shares)	1,966,699	1,966,699
Restricted Stock Unit [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested Stock Awards, Beginning balance (in shares)		419,094
Nonvested Stock Awards, Shares Granted (in shares)		417,377
Nonvested Stock Awards, Shares Vested (in shares)		(151,641)
Nonvested Stock Awards, Shares Forfeited (in shares)		(227,089)
Nonvested Stock Awards Shares, Ending balance (in shares)	457,741	457,741

X

- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

+ 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)(iv)(3)

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-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

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

+ References

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

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

-Publisher FASB

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-Topic 718

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

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-Publisher FASB

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- Definition

The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

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-Subparagraph (c)(2)(iii)(2)

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X

- Definition

The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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