Earnings per Share (Computations Of Basic And Diluted EPS) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Earnings Per Share [Abstract]
Net income (loss) applicable to Helix	$ 1,615	$ 65,727
Less: Income from discontinued operations, net of tax	(1,058)	(48,853)
Income (loss) from continuing operations	557	16,874
Less: Undistributed net income allocable to participating securities	(5)	(174)
Income applicable to common shareholders - continuing operations	552	16,700
Less: Undistributed net income from discontinued operations allocable to participating securities	(8)	(503)
Income applicable to common shareholders - discontinued operations	1,050	48,350
Weighted average number of shares outstanding - basic	105,032	104,530
Share-based awards other than participating securities, Shares	133	98
Undistributed earnings reallocated to participating securities, value		1
Covertible preferred stock		10
Convertible preferred stock, Shares		361
Net income applicable to Helix - Diluted	552	16,711
Weighted average number of shares outstanding, diluted, total	105,165	104,989
Income from discontinued operations, net of tax	$ 1,058	$ 48,853