Annual report pursuant to Section 13 and 15(d)

Long Term Debt (Narratives) (Details)

v3.6.0.2
Long Term Debt (Narratives) (Details)
12 Months Ended
Dec. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
Dec. 31, 2014
USD ($)
Feb. 02, 2015
USD ($)
$ / shares
shares
Debt Instrument [Line Items]        
Debt issuance costs $ 5,451,000 $ 13,979,000 $ 84,000  
Loss on extinguishment of debt 640,000 27,700,000 $ 0  
Long-term debt, gross 1,373,783,000 1,372,113,000    
Letters of credit outstanding 21,000,000      
Unamortized discount $ 21,878,000 24,007,000    
Accrued Interest to Stock Appreciation Right Conversion Rate 0.04      
Stock Appreciation Rights (SARs) | Class A Common Stock        
Debt Instrument [Line Items]        
Stock appreciation rights | shares       3,000,000
Exercise price of rights | $ / shares       $ 13.00
Searchlight ALX, LP Promissory Note [Member] | Stock Appreciation Rights (SARs) | Class A Common Stock        
Debt Instrument [Line Items]        
Stock appreciation rights | shares       3,000,000
Exercise price of rights | $ / shares       $ 13.00
Medium-term Notes [Member] | Senior Credit Facility        
Debt Instrument [Line Items]        
Loan fees and other expenses $ 200,000      
Debt issuance costs 3,900,000      
Loss on extinguishment of debt 600,000      
Line of Credit [Member] | Senior Credit Facility | Revolving Credit Facility        
Debt Instrument [Line Items]        
Long-term debt, gross 55,000,000 0    
Maximum borrowing capacity 200,000,000      
Remaining borrowing capacity 124,000,000      
Senior Notes [Member] | 2025 Notes        
Debt Instrument [Line Items]        
Long-term debt, gross $ 450,000,000 450,000,000    
Frequency of periodic payment semi-annually      
Senior Notes [Member] | 2025 Notes | Minimum        
Debt Instrument [Line Items]        
Percentage of principal 100.00%      
Senior Notes [Member] | 2025 Notes | Maximum        
Debt Instrument [Line Items]        
Percentage of principal 101.00%      
Senior Notes [Member] | 2019 Notes        
Debt Instrument [Line Items]        
Loss on extinguishment of debt   27,700,000    
Senior Notes [Member] | 2021 Notes        
Debt Instrument [Line Items]        
Long-term debt, gross $ 325,000,000 325,000,000    
Frequency of periodic payment Semi-annually      
Senior Notes [Member] | 2021 Notes | Minimum        
Debt Instrument [Line Items]        
Percentage of principal 100.00%      
Senior Notes [Member] | 2021 Notes | Maximum        
Debt Instrument [Line Items]        
Percentage of principal 101.00%      
Unsecured Debt [Member] | Searchlight ALX, LP Promissory Note [Member]        
Debt Instrument [Line Items]        
Long-term debt, gross $ 75,000,000 $ 75,000,000    
Face amount of debt       $ 75,000,000.0
Unamortized discount       $ 21,700,000