Condensed Consolidated Statements of Income (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended									12 Months Ended
	Dec. 31, 2011	Oct. 01, 2011	Jul. 02, 2011	Apr. 02, 2011	Dec. 31, 2010	Oct. 02, 2010	Jul. 03, 2010	Apr. 03, 2010	Jun. 30, 2009	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Condensed Financial Statements, Captions [Line Items]
Net sales	$ 865,692	$ 890,546	$ 910,175	$ 790,273	$ 753,858	$ 773,735	$ 796,167	$ 707,013		$ 3,456,686	$ 3,030,773	$ 2,692,468
Cost of goods sold										2,382,964	2,100,133	1,907,333
Gross profit	264,865	272,062	287,736	249,059	232,228	236,542	248,168	213,702		1,073,722	930,640	785,135
Selling, general and administrative										626,527	529,329	507,303
Research and development										78,158	67,156	57,884
Goodwill impairment										200,520
Operating (loss) income	(119,985)	92,903	109,422	86,177	79,605	90,823	100,126	63,601		168,517	334,155	219,948
Other (income) expense:
Equity income of unconsolidated subsidiaries										(1,898)	(2,108)	1,379
Loss on early extinguishment of debt									4,800			4,804
Net interest (income) expense										58,835	36,116	41,118
Income (loss) from continuing operations before income taxes and noncontrolling interest										111,580	300,147	172,647
Provision for income taxes										73,059	97,200	56,428
Income from continuing operations	(133,704)	52,054	68,137	52,034	49,577	55,729	61,612	36,029		38,521	202,947	116,219
Gain (loss) on disposal of discontinued operations, net of tax					(2,292)	549	593	524			(626)	(19)
Net income before noncontrolling interest										38,521	202,321	116,200
Noncontrolling interest										4,299	4,493	707
Net income attributable to Pentair, Inc.										34,222	197,828	115,493
Net income from continuing operations attributable to Pentair, Inc.	(134,123)	51,092	66,712	50,541	48,668	54,501	60,488	34,797		34,222	198,454	115,512
Parent Company
Condensed Financial Statements, Captions [Line Items]
Cost of goods sold										4,000	3,167	7,024
Gross profit										(4,000)	(3,167)	(7,024)
Selling, general and administrative										18,967	(3,713)	10,074
Research and development										1,032	393	306
Operating (loss) income										(23,999)	153	(17,404)
Earnings from investment in subsidiaries										18,792	(129,872)	(60,528)
Other (income) expense:
Loss on early extinguishment of debt												4,804
Net interest (income) expense										(107,743)	(111,034)	(106,586)
Income (loss) from continuing operations before income taxes and noncontrolling interest										64,952	241,059	144,906
Provision for income taxes										30,730	42,605	29,270
Income from continuing operations											198,454	115,636
Gain (loss) on disposal of discontinued operations, net of tax											(626)	(143)
Net income before noncontrolling interest										34,222	197,828	115,493
Net income attributable to Pentair, Inc.										34,222	197,828	115,493
Net income from continuing operations attributable to Pentair, Inc.											198,454	115,636
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net sales										2,243,362	2,092,487	1,827,463
Cost of goods sold										1,562,298	1,453,786	1,310,011
Gross profit										681,064	638,701	517,452
Selling, general and administrative										338,830	337,408	312,079
Research and development										41,860	42,386	34,844
Operating (loss) income										300,374	258,907	170,529
Earnings from investment in subsidiaries										(27,419)
Other (income) expense:
Equity income of unconsolidated subsidiaries										(1,654)	(1,551)	1,379
Net interest (income) expense										152,264	153,904	153,672
Income (loss) from continuing operations before income taxes and noncontrolling interest										177,183	106,554	15,478
Provision for income taxes										45,156	36,447	6,063
Income from continuing operations											70,107	9,415
Gain (loss) on disposal of discontinued operations, net of tax												551
Net income before noncontrolling interest										132,027	70,107	9,966
Net income attributable to Pentair, Inc.										132,027	70,107	9,966
Net income from continuing operations attributable to Pentair, Inc.											70,107	9,415
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net sales										1,437,242	1,189,597	1,050,381
Cost of goods sold										1,039,362	893,570	775,116
Gross profit										397,880	296,027	275,265
Selling, general and administrative										269,952	196,555	185,708
Research and development										35,266	24,377	22,734
Goodwill impairment										200,520
Operating (loss) income										(107,858)	75,095	66,823
Earnings from investment in subsidiaries										(1,321)
Other (income) expense:
Equity income of unconsolidated subsidiaries										(244)	(557)
Net interest (income) expense										14,314	(6,754)	(5,968)
Income (loss) from continuing operations before income taxes and noncontrolling interest										(120,607)	82,406	72,791
Provision for income taxes										(2,827)	18,148	21,095
Income from continuing operations											64,258	51,696
Gain (loss) on disposal of discontinued operations, net of tax												(427)
Net income before noncontrolling interest										(117,780)	64,258	51,269
Noncontrolling interest										4,299	4,493	707
Net income attributable to Pentair, Inc.										(122,079)	59,765	50,562
Net income from continuing operations attributable to Pentair, Inc.											59,765	50,989
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net sales										(223,918)	(251,311)	(185,376)
Cost of goods sold										(222,696)	(250,390)	(184,818)
Gross profit										(1,222)	(921)	(558)
Selling, general and administrative										(1,222)	(921)	(558)
Earnings from investment in subsidiaries										9,948	129,872	60,528
Other (income) expense:
Income (loss) from continuing operations before income taxes and noncontrolling interest										(9,948)	(129,872)	(60,528)
Income from continuing operations											(129,872)	(60,528)
Net income before noncontrolling interest										(9,948)	(129,872)	(60,528)
Net income attributable to Pentair, Inc.										(9,948)	(129,872)	(60,528)
Net income from continuing operations attributable to Pentair, Inc.											$ (129,872)	$ (60,528)