| **Fair Value Measurements and Derivative Instruments (Derivative Financial Instruments) (Details) - USD ($)**          |                | 6 Months Ended   |
|------------------------------------------------------------------------------------------------------------------------|----------------|------------------|
||
| Stock Appreciation Rights (SARs) [Member]                                                                              |           |             |   |
| **Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]**                |           |             |   |
| Stock appreciation rights, expiration period                                                                           | 8 years        |             |   |
| Volatility                                                                                                             |           | 40.00%           |   |
| Risk-free interest rate                                                                                                |           | 1.20%            |   |
| **Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]** |           |             |   |
| Fair value of stock appreciation rights, beginning balance                                                             |           | $ 32,820,000     | $ 0 |
| Issuance                                                                                                               |           |             | 21,660,000 |
| Fair value of stock appreciation rights, ending balance                                                                |           | 21,780,000       | 26,730,000 |
| Stock Appreciation Rights (SARs) [Member] | Other Income (Expense) [Member]                                            |           |             |   |
| **Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]** |           |             |   |
| Fair value adjustment at end of period, included in Other Income (Expense)                                             |           | $ (11,040,000)   | $ 5,070,000 |
| Stock Appreciation Rights (SARs) [Member] | Minimum [Member]                                                           |           |             |   |
| **Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]**                |           |             |   |
| Contractual term (in years)                                                                                            |           | 2 years 7 months |   |
| Stock Appreciation Rights (SARs) [Member] | Maximum [Member]                                                           |           |             |   |
| **Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]**                |           |             |   |
| Contractual term (in years)                                                                                            |           | 6 years 7 months |   |
| Stock Appreciation Rights (SARs) [Member] | Common Stock - Class A [Member]                                            |           |             |   |
| **Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]**                |           |             |   |
| Stock appreciation rights (in rights)                                                                                  | 3,000,000      |             |   |
| Exercise price of stock appreciation rights (per share)                                                                | $ 13.00        |             |   |
| Searchlight ALX, LP Promissory Note [Member] | Unsecured Debt [Member]                                                 |           |             |   |
| **Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]**                |           |             |   |
| Debt face amount                                                                                                       | $ 75,000,000.0 |             |   |

| X                                                                                                                                                                                                                                                                     |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Stock Appreciation Rights, Expiration Date
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Exercise price per share or per unit of warrants or rights outstanding.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)(4)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number of warrants or rights outstanding.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Face (par) amount of debt instrument at time of issuance.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399
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| X                                                                                                                                                                                                                                                                                                                                                                                              |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Period the derivative contract is outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Risk-free interest rate assumption used in valuing an instrument.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                               |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.
+ References
No definition available.
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|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.
+ References
No definition available.
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of gain (loss) recognized on the income statement for financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of issuances of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.
+ References
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.
+ References
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| X                                                                                                                                                                   |
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| X                                                                                                                               |
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| X                                                                                                                                                             |
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| X                                                                                                                                                |
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