XML 91 R75.htm IDEA: XBRL DOCUMENT v3.8.0.1
Fair Value of financial instruments - Additional Information (Detail)
$ in Thousands
Mar. 31, 2018
USD ($)
Estimate of Fair Value Measurement | Senior Secured Credit Facilities  
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]  
Long-term debt value $ 4,616,019
Estimate of Fair Value Measurement | Senior Notes  
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]  
Long-term debt value 4,433,500
Reported Value Measurement | Senior Secured Credit Facilities  
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]  
Long-term debt value 4,546,990
Reported Value Measurement | Senior Notes  
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]  
Long-term debt value $ 4,461,802