Earnings per Share (Computations Of Basic And Diluted EPS) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Earnings Per Share [Abstract]
Net income (loss) applicable to Helix	$ 27,211	$ 44,641	$ 28,826	$ 110,368
Less: Income from discontinued operations, net of tax	29	(42,216)	(1,029)	(91,069)
Income (loss) from continuing operations	27,240	2,425	27,797	19,299
Less: Undistributed net income allocable to participating securities	(203)	(24)	(201)	(194)
Income applicable to common shareholders - continuing operations	27,037	2,401	27,596	19,105
Less: Undistributed net income from discontinued operations allocable to participating securities		(424)	(7)	(917)
Income applicable to common shareholders - discontinued operations	(29)	41,792	1,022	90,152
Weighted average number of shares outstanding - basic	105,046	104,563	105,039	104,547
Share-based awards other than participating securities, Shares	87	118	102	104
Undistributed earnings reallocated to participating securities, value			1	1
Covertible preferred stock		10		20
Convertible preferred stock, Shares		361		361
Net income applicable to Helix - Diluted	27,037	2,411	27,597	19,126
Weighted average number of shares outstanding, diluted, total	105,133	105,042	105,141	105,012
Income from discontinued operations, net of tax	$ (29)	$ 42,216	$ 1,029	$ 91,069