Condensed Consolidated Balance Sheets (Unaudited) (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jul. 02, 2011	Dec. 31, 2010
Current assets
Cash and cash equivalents	$ 60,598	$ 50,077	$ 68,972	$ 46,056
Accounts and notes receivable, net	572,144	569,204	595,407
Inventories	460,039	449,863	484,795
Deferred tax assets	58,899	60,899	60,833
Prepaid expenses and other current assets	124,345	107,792	124,632
Total current assets	1,276,025	1,237,835	1,334,639
Property, plant and equipment, net	381,063	387,525	410,547
Other assets
Goodwill	2,255,134	2,273,918	2,573,430	2,066,044
Intangibles, net	570,503	592,285	654,908
Other	103,544	94,750	78,788
Total other assets	2,929,181	2,960,953	3,307,126
Total assets	4,586,269	4,586,313	5,052,312
Current liabilities
Short-term borrowings	222	3,694	21,451
Current maturities of long-term debt	1,193	1,168	1,289
Accounts payable	288,265	294,858	315,403
Employee compensation and benefits	89,514	109,361	108,836
Current pension and post-retirement benefits	9,052	9,052	8,733
Accrued product claims and warranties	44,935	42,630	47,259
Income taxes	32,228	14,547	21,498
Accrued rebates and sales incentives	45,870	37,009	42,567
Other current liabilities	150,437	129,522	144,366
Total current liabilities	661,716	641,841	711,402
Other liabilities
Long-term debt	1,233,794	1,304,225	1,384,167
Pension and other retirement compensation	247,324	248,615	217,021
Post-retirement medical and other benefits	29,921	31,774	27,954
Long-term income taxes payable	13,294	26,470	23,832
Deferred tax liabilities	190,173	188,957	235,422
Other non-current liabilities	92,175	97,039	85,660
Total liabilities	2,468,397	2,538,921	2,685,458
Shareholders' equity attributable to Pentair, Inc.	2,001,789	1,933,329	2,249,354
Noncontrolling interest	116,083	114,063	117,500
Total shareholders' equity	2,117,872	2,047,392	2,366,854	2,205,032
Total liabilities and shareholders' equity	4,586,269	4,586,313	5,052,312
Parent Company
Current assets
Cash and cash equivalents	6,135	3,097	4,836	3,201
Accounts and notes receivable, net	736	828	796
Deferred tax assets	130,151	134,240	113,205
Prepaid expenses and other current assets	44,061	28,937	8,958
Total current assets	181,083	167,102	127,795
Property, plant and equipment, net	17,953	19,693	20,172
Other assets
Investments in/advances to subsidiaries	2,911,498	2,910,927	2,856,562
Other	65,638	63,508	75,538
Total other assets	2,977,136	2,974,435	2,932,100
Total assets	3,176,172	3,161,230	3,080,067
Current liabilities
Current maturities of long-term debt		2,585	2,905
Accounts payable	5,334	5,036	5,781
Employee compensation and benefits	15,771	24,466	32,294
Current pension and post-retirement benefits	9,052	9,052	8,733
Accrued product claims and warranties	165	165	12,248
Income taxes	35,498	40,999	9,106
Other current liabilities	30,824	25,050	14,874
Total current liabilities	96,644	107,353	85,941
Other liabilities
Long-term debt	1,245,055	1,312,053	1,265,400
Pension and other retirement compensation	185,513	182,556	136,901
Post-retirement medical and other benefits	17,512	17,024	17,679
Long-term income taxes payable	13,294	26,470	23,832
Deferred tax liabilities			10
Due to (from) affiliates	(442,406)	(479,943)	(743,661)
Other non-current liabilities	58,771	62,388	44,611
Total liabilities	1,174,383	1,227,901	830,713
Shareholders' equity attributable to Pentair, Inc.	2,001,789	1,933,329	2,249,354
Total shareholders' equity	2,001,789	1,933,329	2,249,354
Total liabilities and shareholders' equity	3,176,172	3,161,230	3,080,067
Guarantor Subsidiaries
Current assets
Cash and cash equivalents	14,339	3,332	4,651	3,404
Accounts and notes receivable, net	348,556	360,027	317,365
Inventories	241,629	227,472	203,998
Deferred tax assets	40,698	40,698	40,363
Prepaid expenses and other current assets	12,282	(6,886)	14,973
Total current assets	657,504	624,643	581,350
Property, plant and equipment, net	132,314	136,102	110,551
Other assets
Investments in/advances to subsidiaries	1,414,260	1,447,522	599,056
Goodwill	1,330,265	1,330,265	1,471,582
Intangibles, net	243,431	250,792	217,311
Other	8,931	27,337	4,821
Total other assets	2,996,887	3,055,916	2,292,770
Total assets	3,786,705	3,816,661	2,984,671
Current liabilities
Accounts payable	188,673	189,355	160,537
Employee compensation and benefits	19,855	30,015	22,791
Accrued product claims and warranties	24,385	22,037	22,574
Income taxes	(1,801)	(28,717)	5,720
Accrued rebates and sales incentives	36,212	25,612	32,219
Other current liabilities	64,436	53,960	37,558
Total current liabilities	331,760	292,262	281,399
Other liabilities
Long-term debt	2,417,922	2,417,922	2,417,890
Pension and other retirement compensation	(10,541)	(7,701)	38
Post-retirement medical and other benefits	31,549	33,890	35,323
Deferred tax liabilities	229,962	229,962	213,201
Due to (from) affiliates	675,455	751,145	(261,361)
Other non-current liabilities	1,323	1,508	1,701
Total liabilities	3,677,430	3,718,988	2,688,191
Shareholders' equity attributable to Pentair, Inc.	109,275	97,673	296,480
Total shareholders' equity	109,275	97,673	296,480
Total liabilities and shareholders' equity	3,786,705	3,816,661	2,984,671
Non-Guarantor Subsidiaries
Current assets
Cash and cash equivalents	40,124	43,648	59,485	39,451
Accounts and notes receivable, net	281,087	263,201	375,242
Inventories	218,410	222,391	280,797
Deferred tax assets	12,674	13,382	13,247
Prepaid expenses and other current assets	107,023	107,121	118,638
Total current assets	659,318	649,743	847,409
Property, plant and equipment, net	230,796	231,730	279,824
Other assets
Investments in/advances to subsidiaries	85,952	92,396	686,070
Goodwill	924,869	943,653	1,101,848
Intangibles, net	327,072	341,493	437,597
Other	48,115	23,045	23,477
Total other assets	1,386,008	1,400,587	2,248,992
Total assets	2,276,122	2,282,060	3,376,225
Current liabilities
Short-term borrowings	222	3,694	21,451
Current maturities of long-term debt	1,193	1,168	29,220
Accounts payable	152,549	152,065	247,182
Employee compensation and benefits	53,888	54,880	53,751
Accrued product claims and warranties	20,385	20,428	12,437
Income taxes	(1,469)	2,265	6,672
Accrued rebates and sales incentives	9,658	11,397	10,348
Other current liabilities	94,191	71,890	110,149
Total current liabilities	330,617	317,787	491,210
Other liabilities
Long-term debt	520,265	542,411	1,033,600
Pension and other retirement compensation	72,352	73,760	80,082
Deferred tax liabilities	84,835	86,416	128,192
Due to (from) affiliates	601,727	711,705	1,024,935
Other non-current liabilities	32,081	33,143	39,348
Total liabilities	1,641,877	1,765,222	2,797,367
Shareholders' equity attributable to Pentair, Inc.	518,162	402,775	461,358
Noncontrolling interest	116,083	114,063	117,500
Total shareholders' equity	634,245	516,838	578,858
Total liabilities and shareholders' equity	2,276,122	2,282,060	3,376,225
Eliminations
Current assets
Accounts and notes receivable, net	(58,235)	(54,852)	(97,996)
Deferred tax assets	(124,624)	(127,421)	(105,982)
Prepaid expenses and other current assets	(39,021)	(21,380)	(17,937)
Total current assets	(221,880)	(203,653)	(221,915)
Other assets
Investments in/advances to subsidiaries	(4,411,710)	(4,450,845)	(4,141,688)
Other	(19,140)	(19,140)	(25,048)
Total other assets	(4,430,850)	(4,469,985)	(4,166,736)
Total assets	(4,652,730)	(4,673,638)	(4,388,651)
Current liabilities
Current maturities of long-term debt		(2,585)	(30,836)
Accounts payable	(58,291)	(51,598)	(98,097)
Other current liabilities	(39,014)	(21,378)	(18,215)
Total current liabilities	(97,305)	(75,561)	(147,148)
Other liabilities
Long-term debt	(2,949,448)	(2,968,161)	(3,332,723)
Post-retirement medical and other benefits	(19,140)	(19,140)	(25,048)
Deferred tax liabilities	(124,624)	(127,421)	(105,981)
Due to (from) affiliates	(834,776)	(982,907)	(19,913)
Total liabilities	(4,025,293)	(4,173,190)	(3,630,813)
Shareholders' equity attributable to Pentair, Inc.	(627,437)	(500,448)	(757,838)
Total shareholders' equity	(627,437)	(500,448)	(757,838)
Total liabilities and shareholders' equity	$ (4,652,730)	$ (4,673,638)	$ (4,388,651)