Organization, Proposed Merger And Bases Of Presentation (Impact Of Tax Correction To The Consolidated Balance Sheet) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Deferred income taxes, net - current	$ 21,388	$ 21,647
Total current assets	477,077	498,068
Total assets	1,673,283	1,699,518
Income taxes payable - current	14,654	14,482
Total current liabilities	558,217	605,583
Total liabilities	760,028	809,984
Retained earnings	335,725	333,057
Total Quest Software Inc. stockholders' equity	878,373	854,585
Total equity	891,255	867,534
Total liabilities and equity	1,673,283	1,699,518
As Previously Reported [Member]
Deferred income taxes, net - current		19,780
Total current assets		496,201
Total assets		1,697,651
Income taxes payable - current
Total current liabilities		591,101
Total liabilities		795,502
Retained earnings		345,672
Total Quest Software Inc. stockholders' equity		867,200
Total equity		880,149
Total liabilities and equity		1,697,651
As Corrected [Member]
Deferred income taxes, net - current		21,647
Total current assets		498,068
Total assets		1,699,518
Income taxes payable - current		14,482
Total current liabilities		605,583
Total liabilities		809,984
Retained earnings		333,057
Total Quest Software Inc. stockholders' equity		854,585
Total equity		867,534
Total liabilities and equity		1,699,518
Increase/(Decrease) [Member]
Deferred income taxes, net - current		1,867
Total current assets		1,867
Total assets		1,867
Income taxes payable - current		14,482
Total current liabilities		14,482
Total liabilities		14,482
Retained earnings		(12,615)
Total Quest Software Inc. stockholders' equity		(12,615)
Total equity		(12,615)
Total liabilities and equity		$ 1,867