Condensed Consolidated Balance Sheets (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Current assets
Cash and cash equivalents	$ 50,077	$ 46,056	$ 33,396	$ 39,344
Accounts and notes receivable, net	569,204	516,905
Inventories	449,863	405,356
Deferred tax assets	60,899	56,349
Prepaid expenses and other current assets	107,792	44,631
Total current assets	1,237,835	1,069,297
Property, plant and equipment, net	387,525	329,435	333,688
Other assets
Goodwill	2,273,918	2,066,044	2,088,797
Intangibles, net	592,285	453,570
Other	94,750	55,187
Total other assets	2,960,953	2,574,801
Total assets	4,586,313	3,973,533	3,911,334
Current liabilities
Short-term borrowings	3,694	4,933
Current maturities of long-term debt	1,168	18
Accounts payable	294,858	262,357
Employee compensation and benefits	109,361	107,995
Current pension and post-retirement benefits	9,052	8,733
Accrued product claims and warranties	42,630	42,295
Income taxes	14,547	5,964
Accrued rebates and sales incentives	37,009	33,559
Other current liabilities	129,522	80,942
Total current liabilities	641,841	546,796
Other liabilities
Long-term debt	1,304,225	702,521
Pension and other retirement compensation	248,615	209,859
Post-retirement medical and other benefits	31,774	30,325
Long-term income taxes payable	26,470	23,507
Deferred tax liabilities	188,957	169,198
Other non-current liabilities	97,039	86,295
Total liabilities	2,538,921	1,768,501
Noncontrolling interest	114,063	111,879
Shareholders' equity attributable to Pentair, Inc.	1,933,329	2,093,153
Total liabilities and shareholders' equity	4,586,313	3,973,533
Parent Company
Current assets
Cash and cash equivalents	3,097	3,201	2,032	2,720
Accounts and notes receivable, net	828	678
Deferred tax assets	134,240	115,722
Prepaid expenses and other current assets	28,937	8,278
Total current assets	167,102	127,879
Property, plant and equipment, net	19,693	17,392
Other assets
Investments in/advances to subsidiaries	2,910,927	2,355,343
Other	63,508	56,052
Total other assets	2,974,435	2,411,395
Total assets	3,161,230	2,556,666
Current liabilities
Current maturities of long-term debt	2,585	135,678
Accounts payable	5,036	4,908
Employee compensation and benefits	24,466	38,513
Current pension and post-retirement benefits	9,052	8,733
Accrued product claims and warranties	165	12,245
Income taxes	40,999	4,788
Other current liabilities	25,050	9,772
Total current liabilities	107,353	214,637
Other liabilities
Long-term debt	1,312,053	702,500
Pension and other retirement compensation	182,556	136,750
Post-retirement medical and other benefits	17,024	18,388
Long-term income taxes payable	26,470	23,507
Deferred tax liabilities		5
Due to/ (from) affiliates	(479,943)	(678,966)
Other non-current liabilities	62,388	46,692
Total liabilities	1,227,901	463,513
Shareholders' equity attributable to Pentair, Inc.	1,933,329	2,093,153
Total liabilities and shareholders' equity	3,161,230	2,556,666
Guarantor Subsidiaries
Current assets
Cash and cash equivalents	3,332	3,404	1,813	3,345
Accounts and notes receivable, net	360,027	357,730
Inventories	227,472	232,369
Deferred tax assets	40,698	40,064
Prepaid expenses and other current assets	(6,886)	10,098
Total current assets	624,643	643,665
Property, plant and equipment, net	136,102	144,332
Other assets
Investments in/advances to subsidiaries	1,447,522	89,659
Goodwill	1,330,265	1,549,537
Intangibles, net	250,792	265,987
Other	27,337	4,045
Total other assets	3,055,916	1,909,228
Total assets	3,816,661	2,697,225
Current liabilities
Accounts payable	189,355	170,747
Employee compensation and benefits	30,015	32,167
Accrued product claims and warranties	22,037	23,410
Income taxes	(28,717)	633
Accrued rebates and sales incentives	25,612	23,500
Other current liabilities	53,960	33,227
Total current liabilities	292,262	283,684
Other liabilities
Long-term debt	2,417,922	1,947,400
Pension and other retirement compensation	(7,701)	112
Post-retirement medical and other benefits	33,890	36,986
Deferred tax liabilities	229,962	213,385
Due to/ (from) affiliates	751,145	(80,779)
Other non-current liabilities	1,508	1,892
Total liabilities	3,718,988	2,402,680
Shareholders' equity attributable to Pentair, Inc.	97,673	294,545
Total liabilities and shareholders' equity	3,816,661	2,697,225
Non-Guarantor Subsidiaries
Current assets
Cash and cash equivalents	43,648	39,451	29,551	33,279
Accounts and notes receivable, net	263,201	222,319
Inventories	222,391	172,987
Deferred tax assets	13,382	7,928
Prepaid expenses and other current assets	107,121	51,497
Total current assets	649,743	494,182
Property, plant and equipment, net	231,730	167,711
Other assets
Investments in/advances to subsidiaries	92,396	748,181
Goodwill	943,653	516,507
Intangibles, net	341,493	187,583
Other	23,045	20,139
Total other assets	1,400,587	1,472,410
Total assets	2,282,060	2,134,303
Current liabilities
Short-term borrowings	3,694	4,933
Current maturities of long-term debt	1,168	18,154
Accounts payable	152,065	150,517
Employee compensation and benefits	54,880	37,315
Accrued product claims and warranties	20,428	6,640
Income taxes	2,265	543
Accrued rebates and sales incentives	11,397	10,059
Other current liabilities	71,890	63,185
Total current liabilities	317,787	291,346
Other liabilities
Long-term debt	542,411	377,539
Pension and other retirement compensation	73,760	72,997
Deferred tax liabilities	86,416	63,173
Due to/ (from) affiliates	711,705	810,652
Other non-current liabilities	33,143	37,711
Total liabilities	1,765,222	1,653,418
Noncontrolling interest	114,063	111,879
Shareholders' equity attributable to Pentair, Inc.	402,775	369,006
Total liabilities and shareholders' equity	2,282,060	2,134,303
Eliminations
Current assets
Accounts and notes receivable, net	(54,852)	(63,822)
Deferred tax assets	(127,421)	(107,365)
Prepaid expenses and other current assets	(21,380)	(25,242)
Total current assets	(203,653)	(196,429)
Other assets
Investments in/advances to subsidiaries	(4,450,845)	(3,193,183)
Other	(19,140)	(25,049)
Total other assets	(4,469,985)	(3,218,232)
Total assets	(4,673,638)	(3,414,661)
Current liabilities
Current maturities of long-term debt	(2,585)	(153,814)
Accounts payable	(51,598)	(63,815)
Other current liabilities	(21,378)	(25,242)
Total current liabilities	(75,561)	(242,871)
Other liabilities
Long-term debt	(2,968,161)	(2,324,918)
Post-retirement medical and other benefits	(19,140)	(25,049)
Deferred tax liabilities	(127,421)	(107,365)
Due to/ (from) affiliates	(982,907)	(50,907)
Total liabilities	(4,173,190)	(2,751,110)
Shareholders' equity attributable to Pentair, Inc.	(500,448)	(663,551)
Total liabilities and shareholders' equity	$ (4,673,638)	$ (3,414,661)