Condensed Consolidating Financial Information (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
ASSETS
Current assets	$ 200,025	$ 328,151
Property and equipment	1,987,848	1,867,766
Other assets	15,752	16,552
Total Assets	2,203,625	2,212,469
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	192,677	211,794
Long-term liabilities	1,005,305	1,004,166
Stockholders' equity	1,005,643	996,509
Total Liabilities and Stockholders' Equity	2,203,625	2,212,469
Swift Energy Company (Issuer) [Member]
ASSETS
Investment in subsidiaries (equity method)	1,005,643	996,509
Total Assets	1,005,643	996,509
LIABILITIES AND STOCKHOLDERS' EQUITY
Stockholders' equity	1,005,643	996,509
Total Liabilities and Stockholders' Equity	1,005,643	996,509
Swift Energy Operating, LLC (Guarantor) [Member]
ASSETS
Current assets	200,004	328,130
Property and equipment	1,987,848	1,867,766
Other assets	15,752	16,552
Total Assets	2,203,604	2,212,448
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	192,675	211,792
Long-term liabilities	1,090,734	1,089,595
Stockholders' equity	920,195	911,061
Total Liabilities and Stockholders' Equity	2,203,604	2,212,448
Other Subsidiaries [Member]
ASSETS
Current assets	21	21
Investment in subsidiaries (equity method)	920,195	911,061
Other assets	85,429	85,429
Total Assets	1,005,645	996,511
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	2	2
Stockholders' equity	1,005,643	996,509
Total Liabilities and Stockholders' Equity	1,005,645	996,511
Eliminations [Member]
ASSETS
Investment in subsidiaries (equity method)	(1,925,838)	(1,907,570)
Other assets	(85,429)	(85,429)
Total Assets	(2,011,267)	(1,992,999)
LIABILITIES AND STOCKHOLDERS' EQUITY
Long-term liabilities	(85,429)	(85,429)
Stockholders' equity		(1,907,570)
Total Liabilities and Stockholders' Equity	$ (2,011,267)	$ (1,992,999)