Acquisition and Dispositions - Additional Information (Detail) (USD $)	3 Months Ended					12 Months Ended		1 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013 Multi Function Support Vessel Vessel	Mar. 31, 2013 Charter Fleet Business	Mar. 31, 2012 Charter Fleet Business	Dec. 31, 2011 Charter Fleet Business	Mar. 19, 2012 Charter Fleet Business Vessel	Mar. 19, 2012 Secunda International Limited Vessel
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total purchase consideration	$ 9,000,000
Purchase consideration - cash	6,000,000
Purchase consideration - restricted shares	313,580
Number of vessels held for sale			3
Proceeds from sale of discontinued assets	32,000,000
Gain on sale of the Bold Endurance	12,500,000
Number of vessels operated							10
Number of vessels								14
Cash Proceeds from sale of business				61,000,000
Gain on sale		257,000		300,000	257,000
Write-down of charter fleet business						$ 22,000,000