Stock-Based Compensation, Dividend Restrictions, And Calculations Of Earnings Per Share Of Common Stock (Schedule of Restricted Stock And Restricted Stock Units) (Details) (USD $)	12 Months Ended
Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares outstanding, beginning balance	903,077
Granted, number of shares	532,874
Vested, number of shares	(208,388)
Forfeited, number of shares	(50,204)
Number of shares outstanding, ending balance	1,177,359
Time-Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares outstanding, beginning balance	316,194
Vested, number of shares	(63,764)
Forfeited, number of shares	(10,741)
Number of shares outstanding, ending balance	241,689
Weighted average grant date fair value, beginning of period	18.15
Vested, weighted average grant date fair value	23.70
Forfeited, weighted average grant date fair value	17.06
Weighted average grant date fair value, ending of period	16.74
Performance-Based Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares outstanding, beginning balance	586,883
Granted, number of shares	354,979
Vested, number of shares	(144,451)
Forfeited, number of shares	(32,272)
Number of shares outstanding, ending balance	765,139
Weighted average grant date fair value, beginning of period	20.75
Granted, weighted average grant date fair value	19.56
Vested, weighted average grant date fair value	25.36
Forfeited, weighted average grant date fair value	21.78
Weighted average grant date fair value, ending of period	19.28
Time-Based Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, number of shares	177,895
Vested, number of shares	(173)
Forfeited, number of shares	(7,191)
Number of shares outstanding, ending balance	170,531
Granted, weighted average grant date fair value	18.87
Vested, weighted average grant date fair value	18.84
Forfeited, weighted average grant date fair value	18.84
Weighted average grant date fair value, ending of period	18.87

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).

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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.

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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.

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- 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.

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