Long-Term Debt and Notes Payable - Summary of Long-Term Debt Obligations (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Long-term debt consists of:
Long-term borrowing	$ 854,162	$ 864,469
Less: Amounts due within one year	27,690	27,026
Long-Term Debt	826,472	837,443
Senior Notes [Member]
Long-term debt consists of:
Long-term borrowing	490,864	490,354
Term Loan [Member]
Long-term debt consists of:
Long-term borrowing	290,643	291,424
Amortizing Notes [Member]
Long-term debt consists of:
Long-term borrowing	27,366	33,258
Capital lease obligation [Member]
Long-term debt consists of:
Long-term borrowing	2,719	2,802
Other financing [Member]
Long-term debt consists of:
Long-term borrowing	495	743
North Ocean 105 [Member]
Long-term debt consists of:
Long-term borrowing	$ 42,075	$ 45,888