XML 61 R51.htm IDEA: XBRL DOCUMENT v3.10.0.1
Derivative Instruments - Narrative (Details) - USD ($)
3 Months Ended 9 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
May 08, 2018
Derivative [Line Items]          
Interest expense $ 5,085,000 $ 11,510,000 $ 21,550,000 $ 41,387,000  
LIBOR | Interest rate cap          
Derivative [Line Items]          
Derivative, cap interest rate, percent         2.50%
Notional amount         $ 400,000,000
Interest expense     $ 300,000