Annual report pursuant to Section 13 and 15(d)

Long-Term Debt - Summary of Interest Received and Paid under Term of Cash Flow Swap (Parenthetical) (Detail)

v3.8.0.1
Long-Term Debt - Summary of Interest Received and Paid under Term of Cash Flow Swap (Parenthetical) (Detail)
$ in Thousands
 12 Months Ended
Dec. 31, 2017
USD ($)
Derivatives, Fair Value [Line Items]  
One-month LIBOR rate 1.564%
Receive Rate one-month LIBOR
Cash Flow Swap 2 [Member]  
Derivatives, Fair Value [Line Items]  
Receive Rate one-month LIBOR
Swap agreement effective date Jul. 02, 2018
Cash Flow Swap 3 [Member]  
Derivatives, Fair Value [Line Items]  
Receive Rate one-month LIBOR
Swap agreement effective date Jul. 02, 2018
Cash Flow Swap 5 [Member]  
Derivatives, Fair Value [Line Items]  
Receive Rate one-month LIBOR
Swap agreement effective date Jul. 02, 2018
Cash Flow Swap 4 [Member]  
Derivatives, Fair Value [Line Items]  
Receive Rate one-month LIBOR
Swap agreement effective date Jul. 01, 2019
Cash Flow Swap 6 [Member]  
Derivatives, Fair Value [Line Items]  
Receive Rate one-month LIBOR
Swap agreement effective date Jul. 01, 2019
Cash Flow Swap 8 [Member]  
Derivatives, Fair Value [Line Items]  
Receive Rate one-month LIBOR
Derivative notional amount interest rate caps, remainder of fiscal year $ 62,500
Derivative notional amount interest rate caps, second year 93,750
Derivative notional amount interest rate caps, third year 78,125
Derivative notional amount interest rate caps, fourth year 37,500
Payment of interest rate $ 0
Cash Flow Swap 9 [Member]  
Derivatives, Fair Value [Line Items]  
Receive Rate one-month LIBOR
Derivative notional amount interest rate caps, remainder of fiscal year $ 62,500
Derivative notional amount interest rate caps, second year 93,750
Derivative notional amount interest rate caps, third year 78,125
Derivative notional amount interest rate caps, fourth year 37,500
Payment of interest rate $ 0
Cash Flow Swap 10 [Member]  
Derivatives, Fair Value [Line Items]  
Receive Rate one-month LIBOR
Derivative notional amount interest rate caps, remainder of fiscal year $ 62,500
Derivative notional amount interest rate caps, second year 93,750
Derivative notional amount interest rate caps, third year 78,125
Derivative notional amount interest rate caps, fourth year 37,500
Payment of interest rate $ 0
Cash Flow Swap 11 [Member]  
Derivatives, Fair Value [Line Items]  
Receive Rate one-month LIBOR
Derivative notional amount interest rate caps, remainder of fiscal year $ 62,500
Derivative notional amount interest rate caps, second year 93,750
Derivative notional amount interest rate caps, third year 78,125
Derivative notional amount interest rate caps, fourth year 37,500
Payment of interest rate $ 0