Condensed Consolidated Statement of Income (Detail) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2011	Jul. 03, 2010	Jul. 02, 2011	Jul. 03, 2010
Condensed Financial Statements, Captions [Line Items]
Net sales	$ 910,175	$ 796,167	$ 1,700,448	$ 1,503,180
Cost of goods sold	622,439	547,999	1,163,653	1,041,310
Gross profit	287,736	248,168	536,795	461,870
Selling, general and administrative	158,432	131,043	303,192	263,933
Research and development	19,882	16,999	38,004	34,210
Operating (loss) income	109,422	100,126	195,599	163,727
Other (income) expense:
Equity (income) losses of unconsolidated subsidiaries	(672)	(1,375)	(907)	(1,459)
Net interest (income) expense	14,613	8,569	23,938	18,096
Income (loss) from continuing operations before income taxes and noncontrolling interest	95,481	92,932	172,568	147,090
Provision for income taxes	27,344	31,320	52,397	49,449
Income from continuing operations	68,137	61,612	120,171	97,641
Gain on disposal of discontinued operations, net of tax		593		1,117
Net income before noncontrolling interest	68,137	62,205	120,171	98,758
Noncontrolling interest	1,425	1,124	2,918	2,356
Net income attributable to Pentair, Inc.	66,712	61,081	117,253	96,402
Net income from continuing operations attributable to Pentair, Inc.	66,712	60,488	117,253	95,285
Parent Company
Condensed Financial Statements, Captions [Line Items]
Selling, general and administrative	6,664	1,243	13,272	251
Research and development	435	136	605	272
Operating (loss) income	(7,099)	(1,379)	(13,877)	(523)
Earnings from investment in subsidiaries	(53,988)	(43,799)	(91,295)	(60,959)
Other (income) expense:
Equity (income) losses of unconsolidated subsidiaries	(607)		(783)
Net interest (income) expense	(26,636)	(28,227)	(54,016)	(55,508)
Income (loss) from continuing operations before income taxes and noncontrolling interest	74,132	70,647	132,217	115,944
Provision for income taxes	7,420	10,159	14,964	20,659
Income from continuing operations	66,712	60,488	117,253	95,285
Gain on disposal of discontinued operations, net of tax		593		1,117
Net income before noncontrolling interest	66,712	61,081	117,253	96,402
Net income attributable to Pentair, Inc.	66,712	61,081	117,253	96,402
Net income from continuing operations attributable to Pentair, Inc.	66,712	60,488	117,253	95,285
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net sales	586,395	567,505	1,101,449	1,043,860
Cost of goods sold	399,270	391,677	754,831	723,400
Gross profit	187,125	175,828	346,618	320,460
Selling, general and administrative	83,632	84,171	168,751	164,699
Research and development	10,509	10,874	21,355	21,718
Operating (loss) income	92,984	80,783	156,512	134,043
Other (income) expense:
Equity (income) losses of unconsolidated subsidiaries		(938)		(1,022)
Net interest (income) expense	38,107	38,484	76,593	76,978
Income (loss) from continuing operations before income taxes and noncontrolling interest	54,877	43,237	79,919	58,087
Provision for income taxes	18,301	16,155	26,782	21,419
Income from continuing operations	36,576	27,082	53,137	36,688
Net income before noncontrolling interest	36,576	27,082	53,137	36,668
Net income attributable to Pentair, Inc.	36,576	27,082	53,137	36,668
Net income from continuing operations attributable to Pentair, Inc.	36,576	27,082	53,137	36,668
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net sales	398,634	295,232	740,212	585,662
Cost of goods sold	297,830	222,775	549,560	443,924
Gross profit	100,804	72,457	190,652	141,738
Selling, general and administrative	68,329	45,746	121,644	99,311
Research and development	8,938	5,989	16,044	12,220
Operating (loss) income	23,537	20,722	52,964	30,207
Other (income) expense:
Equity (income) losses of unconsolidated subsidiaries	(65)	(437)	(124)	(437)
Net interest (income) expense	3,142	(1,688)	1,361	(3,374)
Income (loss) from continuing operations before income taxes and noncontrolling interest	20,460	22,847	51,727	34,018
Provision for income taxes	1,623	5,006	10,651	7,371
Income from continuing operations	18,837	17,841	41,076	26,647
Net income before noncontrolling interest	18,837	17,841	41,076	26,647
Noncontrolling interest	1,425	1,124	2,918	2,356
Net income attributable to Pentair, Inc.	17,412	16,717	38,158	24,291
Net income from continuing operations attributable to Pentair, Inc.	17,412	16,717	38,158	24,291
Consolidation, Eliminations
Condensed Financial Statements, Captions [Line Items]
Net sales	(74,854)	(66,570)	(141,213)	(126,342)
Cost of goods sold	(74,661)	(66,453)	(140,738)	(126,014)
Gross profit	(193)	(117)	(475)	(328)
Selling, general and administrative	(193)	(117)	(475)	(328)
Earnings from investment in subsidiaries	53,988	43,799	91,295	60,959
Other (income) expense:
Income (loss) from continuing operations before income taxes and noncontrolling interest	(53,988)	(43,799)	(91,295)	(60,959)
Income from continuing operations	(53,988)	(43,799)	(91,295)	(60,959)
Net income before noncontrolling interest	(53,988)	(43,799)	(91,295)	(60,959)
Net income attributable to Pentair, Inc.	(53,988)	(43,799)	(91,295)	(60,959)
Net income from continuing operations attributable to Pentair, Inc.	$ (53,988)	$ (43,799)	$ (91,295)	$ (60,959)