Long-Term Debt (Schedule of Deferred Financing Costs) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Helix Term Loan [Member]
Gross Carrying Amount			$ 15,318	[1]
Accumulated Amortization			(11,595)	[1]
Net			3,723	[1]
Term Loan Maturing June 2018 [Member]
Gross Carrying Amount	3,630	[2]
Net	3,630	[2]
Revolving Credit Facility Maturing June 2018 [Member]
Gross Carrying Amount	13,261	[2]
Net	13,261	[2]
2025 Notes [Member]
Gross Carrying Amount			8,189
Accumulated Amortization			(8,189)
2032 Notes [Member]
Gross Carrying Amount	3,759		4,251
Accumulated Amortization	(840)		(534)
Net	2,919		3,717
Helix Revolving Loans [Member]
Gross Carrying Amount			20,021	[1]
Accumulated Amortization			(12,466)	[1]
Net			7,555	[1]
Senior Unsecured Notes [Member]
Gross Carrying Amount	10,643	[3]	10,643	[3]
Accumulated Amortization	(8,551)	[3]	(8,252)	[3]
Net	2,092	[3]	2,391	[3]
MARAD Debt [Member]
Gross Carrying Amount	12,200		12,200
Accumulated Amortization	(5,492)		(5,248)
Net	6,708		6,952
Debt [Member]
Gross Carrying Amount	43,493		70,622
Accumulated Amortization	(14,883)		(46,284)
Net	$ 28,610		$ 24,338

[1] Relates to the term loans and revolving credit facility under our former credit agreement, which was terminated in June 2013.

[2] Relates to amounts allocated to the Term Loan and Revolving Credit Facility under our new Credit Agreement, which was entered into in June 2013.

[3] In June 2013, we elected to redeem the remaining Senior Unsecured Notes on July 22, 2013, and we redeemed these notes in full on that date. In July 2013, we recorded a charge of $2.1 million to accelerate the remaining deferred financing costs associated with the original issuance of this debt.