XML 73 R57.htm IDEA: XBRL DOCUMENT v3.8.0.1
Long-Term Debt Schedule of Debt (Details) - USD ($)
$ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Debt Instrument [Line Items]    
Long-term debt $ 407,000  
Senior Notes    
Debt Instrument [Line Items]    
Long-term debt 295,243 $ 196,545
Senior Notes | 5.375% senior notes due 2024    
Debt Instrument [Line Items]    
Long-term debt 295,243 0
Senior Notes | 6.75% senior notes due 2021    
Debt Instrument [Line Items]    
Long-term debt 0 196,545
Line of Credit | 2016 Credit Facility    
Debt Instrument [Line Items]    
Long-term debt $ 107,000 $ 260,000