Summary of Net Properties and Equipment (Detail) $ in Thousands		Mar. 31, 2016 USD ($) Vessel	Mar. 31, 2015 USD ($) Vessel
Property, Plant and Equipment [Line Items]
Number Of Vessels | Vessel		253	263
Carrying Value		$ 3,551,291	$ 3,746,307
Owned Vessels in Active Service
Property, Plant and Equipment [Line Items]
Number Of Vessels | Vessel		180	242
Carrying Value		$ 2,510,418	$ 3,310,476
Stacked Vessels
Property, Plant and Equipment [Line Items]
Number Of Vessels | Vessel		73	21
Carrying Value		$ 794,126	$ 38,489
Marine Equipment and Other Assets Under Construction
Property, Plant and Equipment [Line Items]
Carrying Value		185,380	315,552
Other Property Plant and Equipment
Property, Plant and Equipment [Line Items]
Carrying Value	[1]	$ 61,367	$ 81,790

[1] Other property and equipment includes eight remotely operated vehicles.