v3.19.2
Long-Term Debt - Narrative (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Dec. 31, 2018
Debt Instrument [Line Items]          
Interest expense $ 4,830 $ 4,829 $ 9,659 $ 9,658  
Senior Notes          
Debt Instrument [Line Items]          
Interest expense 4,777 4,776 9,553 9,553  
Accrued interest 1,342   1,342   $ 1,342
Amortization expense, debt issuance costs $ 53 $ 53 $ 106 $ 105  
2013 Senior Notes | Senior Notes          
Debt Instrument [Line Items]          
Redemption price, percentage     100.00%    
Minimum | 2013 Senior Notes | Senior Notes          
Debt Instrument [Line Items]          
Prior notice to be given before redemption date     30 days    
Maximum | 2013 Senior Notes | Senior Notes          
Debt Instrument [Line Items]          
Prior notice to be given before redemption date     60 days