Condensed Consolidating Financial Information (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
ASSETS
Current assets	$ 100,596	$ 158,358
Property and equipment	1,713,190	1,572,845
Investment in subsidiaries (equity method)	0	0
Other assets	12,613	12,713
Total Assets	1,826,399	1,743,916
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	142,541	156,735
Long-term liabilities	733,659	707,164
Total Stockholders' Equity	950,199	880,017
Total Liabilities and Stockholders' Equity	1,826,399	1,743,916
Swift Energy Company (Issuer) [Member]
ASSETS
Current assets	0	0
Property and equipment	0	0
Investment in subsidiaries (equity method)	950,199	880,017
Other assets	0	0
Total Assets	950,199	880,017
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	0	0
Long-term liabilities	0	0
Total Stockholders' Equity	950,199	880,017
Total Liabilities and Stockholders' Equity	950,199	880,017
Swift Energy Operating, LLC (Guarantor) [Member]
ASSETS
Current assets	100,538	158,335
Property and equipment	1,713,190	1,572,845
Investment in subsidiaries (equity method)	0	0
Other assets	12,613	12,713
Total Assets	1,826,341	1,743,893
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	142,509	146,728
Long-term liabilities	819,148	788,385
Total Stockholders' Equity	864,684	808,780
Total Liabilities and Stockholders' Equity	1,826,341	1,743,893
Other Subsidiaries [Member]
ASSETS
Current assets	58	23
Property and equipment	0	0
Investment in subsidiaries (equity method)	864,684	808,780
Other assets	85,489	81,221
Total Assets	950,231	890,024
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	32	10,007
Long-term liabilities	0	0
Total Stockholders' Equity	950,199	880,017
Total Liabilities and Stockholders' Equity	950,231	890,024
Eliminations [Member]
ASSETS
Current assets	0	0
Property and equipment	0	0
Investment in subsidiaries (equity method)	(1,814,883)	(1,688,797)
Other assets	(85,489)	(81,221)
Total Assets	(1,900,372)	(1,770,018)
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	0	0
Long-term liabilities	(85,489)	(81,221)
Total Stockholders' Equity	(1,814,883)	(1,688,797)
Total Liabilities and Stockholders' Equity	$ (1,900,372)	$ (1,770,018)