Stockholders' Equity (Details 1) (USD $)	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Stock option activity in shares and weighted average price
Options outstanding, beginning of period	$ 29.67		$ 29.72		$ 33.22
Options outstanding, beginning of period, shares	1,361,779		1,289,194		1,119,469
Options granted	$ 42.56		$ 25.28		$ 14.66
Options granted, shares	307,394		273,463		273,400
Options canceled	$ 55.19		$ 44.65		$ 33.26
Options canceled, shares	(67,529)		(36,983)		(77,619)
Options exercised	$ 22.61	[1]	$ 18.11	[1]	$ 12.52	[1]
Options exercised, shares	(226,363)	[1]	(163,895)	[1]	(26,056)	[1]
Options outstanding, end of period	$ 32.46		$ 29.67		$ 29.72
Options outstanding, end of period, shares	1,375,281		1,361,779		1,289,194
Options exercisable, end of period	$ 31.07		$ 32.04		$ 31.00
Options exercisable, end of period, shares	734,985		749,447		790,394

[1] The plans allow for the use of a "stock swap" in lieu of a cash exercise for options, under certain circumstances. The delivery of Swift Energy common stock, held by the optionee for a minimum of six months, which are considered mature shares, with a fair market value equal to the required purchase price of the shares to which the exercise relates, constitutes a valid "stock swap." Options issued under a "stock swap" also include a reload feature where additional options are granted at the then current market price when mature shares of Swift stock are used to satisfy the exercise price of an existing stock option grant. The terms of the plans provide that the mature shares delivered, as full or partial payment in a "stock swap", shall again be available for awards under the plans. In 2011 and 2010, 79,194 and 27,463 mature shares were delivered in "stock swap" transactions, respectively, which resulted in the issuance of an equal number of reload option grants. None were issued in 2009.