Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements and Derivative Instruments (Derivative Financial Instruments) (Details)

v3.7.0.1
Fair Value Measurements and Derivative Instruments (Derivative Financial Instruments) (Details) - USD ($)
 3 Months Ended
Feb. 02, 2015
Mar. 31, 2017
Mar. 31, 2016
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   38.00%  
Risk-free interest rate   2.10%  
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]      
Fair value of stock appreciation rights, beginning balance   $ 29,700,000 $ 32,820,000
Fair value of stock appreciation rights, ending balance   32,610,000 28,290,000
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)   $ 2,910,000 $ (4,530,000)
Stock Appreciation Rights (SARs) [Member] | Minimum [Member]      
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Contractual term (in years)   1 year 10 months 1 day  
Stock Appreciation Rights (SARs) [Member] | Maximum [Member]      
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Contractual term (in years)   5 years 10 months 1 day  
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