Share-based Compensation - Restricted Stock, Deferred Stock Units and Deferred Cash Units (Details) (USD $)	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Share-based compensation expense	$ 15,438,000	$ 8,122,000	$ 15,328,000
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Restricted stock awards outstanding - beginning balance	1,813,000	1,965,000
Shares issued, number of shares	1,142,000	955,000
Shares forfeited, number of shares	(212,000)	(608,000)
Shares vested, number of shares	(731,000)	(499,000)
Restricted stock awards outstanding - ending balance	2,012,000	1,813,000	1,965,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Restricted stock awards outstanding, weighted average grant date fair value - beginning balance (in usd per share)	$ 12.68	$ 20.68
Restricted stock awards issued, weighted average grant date fair value (in usd per share)	$ 6.24	$ 7.48
Restricted stock awards forfeited, weighted average grant date fair value (in usd per share)	$ 10.35	$ 17.13
Restricted stock awards vested, weighted average grant date fair value (in usd per share)	$ 17.16	$ 29.44
Restricted stock awards outstanding, weighted average grant date fair value - ending balance (in usd per share)	$ 7.52	$ 12.68	$ 20.68
Fair value on vesting date of vested restricted stock awards	10,381,000	3,888,000	5,864,000
Unrecognized compensation costs related to unvested awards	9,500,000
Unrecognized compensation costs weighted average period for recognition	2 years 6 months 22 days
Deferred Compensation, Share-based Payments [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Shares issued, number of shares	635,000	404,250
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Restricted stock awards issued, weighted average grant date fair value (in usd per share)	$ 6.18	$ 9.24
Unrecognized compensation costs related to unvested awards	8,200,000
Unrecognized compensation costs weighted average period for recognition	1 year 9 months 18 days
Deferred Cash Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Shares issued, number of shares	755,636
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Restricted stock awards issued, weighted average grant date fair value (in usd per share)	$ 6.10
Unrecognized compensation costs related to unvested awards	10,600,000
Unrecognized compensation costs weighted average period for recognition	3 years 4 months 13 days
Share-based compensation expense	$ 2,000,000

As of the balance sheet date, the aggregate unrecognized cost of equity-based awards made to employees under equity-based compensation awards that have yet to vest.

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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

+ References

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-Paragraph 28

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

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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.

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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).

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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

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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

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

-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.

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

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- Definition

The total fair value of equity-based awards 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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- 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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