Summary of Significant Accounting Policies (Computations Of Basic And Diluted EPS) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended												12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accounting Policies [Abstract]
Net income (loss) applicable to Helix	$ 36,503	$ 44,593	$ 27,211	$ 1,615	$ (171,567)	[1]	$ 14,865	[1]	$ 44,641	[1]	$ 65,727	[1]	$ 109,922	$ (46,334)	$ 129,939
Income (loss) from discontinued operations, net of tax		(44)	29	(1,058)	71,888		(4,503)		(42,216)		(48,853)		(1,073)	(23,684)	(95,221)
Income (loss) from continuing operations	36,503	44,549	27,240	557	(99,679)		10,362		2,425		16,874		108,849	(70,018)	34,718
Less: Undistributed net income allocable to participating securities													(801)		(427)
Income applicable to common shareholders - continuing operations													108,048	(70,018)	34,291
Less: Undistributed net income from discontinued operations allocable to participating securities													(8)		(1,172)
Income applicable to common shareholders - discontinued operations													1,065	23,684	94,049
Weighted average number of shares outstanding - basic													105,032	104,449	104,528
Share-based awards other than participating securities, Shares													152		64
Undistributed earnings reallocated to participating securities, value													1		2
Covertible preferred stock, Value															40
Convertible preferred stock, Shares															361
Net income per common share - Diluted													108,049	(70,018)	34,333
Weighted average number of shares outstanding, diluted, total													105,184	104,449	104,953
Income from discontinued operations, net of tax		$ 44	$ (29)	$ 1,058	$ (71,888)		$ 4,503		$ 42,216		$ 48,853		$ 1,073	$ 23,684	$ 95,221

[1] Our net loss in the fourth quarter of 2012 includes a $138.6 million impairment charge associated with the sale of ERT (Note 3).