Condensed Consolidated Statements of Income and Comprehensive Income (Loss) (Unaudited) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jul. 02, 2011	Jun. 30, 2012	Jul. 02, 2011
Condensed Financial Statements, Captions [Line Items]
Net sales	$ 941,525	$ 910,175	$ 1,799,702	$ 1,700,448
Cost of goods sold	629,397	622,439	1,206,855	1,163,653
Gross profit	312,128	287,736	592,847	536,795
Selling, general and administrative	173,445	158,432	348,455	303,192
Research and development	20,891	19,882	41,648	38,004
Operating (loss) income	117,792	109,422	202,744	195,599
Other (income) expense:
Equity income of unconsolidated subsidiaries	(636)	(672)	(1,685)	(907)
Net interest (income) expense	16,079	14,613	30,847	23,938
Income before income taxes and noncontrolling interest	102,349	95,481	173,582	172,568
Provision for income taxes	28,864	27,344	37,943	52,397
Net income before noncontrolling interest	73,485	68,137	135,639	120,171
Noncontrolling interest	1,655	1,425	2,995	2,918
Net income attributable to Pentair, Inc.	71,830	66,712	132,644	117,253
Comprehensive income (loss)	(10,430)	92,306	93,808	187,119
Less: Comprehensive income attributable to noncontrolling interest	(223)	2,216	2,020	5,621
Comprehensive income (loss) attributable to Pentair, Inc.	(10,207)	90,090	91,788	181,498
Parent Company
Condensed Financial Statements, Captions [Line Items]
Selling, general and administrative	11,905	6,664	28,789	13,272
Research and development	245	435	468	605
Operating (loss) income	(12,150)	(7,099)	(29,257)	(13,877)
Earnings from investment in subsidiaries	(62,199)	(53,988)	(115,592)	(91,295)
Other (income) expense:
Equity income of unconsolidated subsidiaries		(607)		(783)
Net interest (income) expense	(27,676)	(26,636)	(56,710)	(54,016)
Income before income taxes and noncontrolling interest	77,725	74,132	143,045	132,217
Provision for income taxes	5,895	7,420	10,401	14,964
Net income before noncontrolling interest	71,830	66,712	132,644	117,253
Net income attributable to Pentair, Inc.	71,830	66,712	132,644	117,253
Comprehensive income (loss)	(10,207)	90,090	91,788	181,498
Comprehensive income (loss) attributable to Pentair, Inc.	(10,207)	90,090	91,788	181,498
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net sales	628,860	586,395	1,186,928	1,101,449
Cost of goods sold	421,655	399,270	807,713	754,831
Gross profit	207,205	187,125	379,215	346,618
Selling, general and administrative	85,781	83,632	174,144	168,751
Research and development	10,958	10,509	21,568	21,355
Operating (loss) income	110,466	92,984	183,503	156,512
Earnings from investment in subsidiaries	(527)		(1,325)
Other (income) expense:
Equity income of unconsolidated subsidiaries	(636)		(1,544)
Net interest (income) expense	38,301	38,107	76,484	76,593
Income before income taxes and noncontrolling interest	73,328	54,877	109,888	79,919
Provision for income taxes	23,935	18,301	24,242	26,782
Net income before noncontrolling interest	49,393	36,576	85,646	53,137
Net income attributable to Pentair, Inc.	49,393	36,576	85,646	53,137
Comprehensive income (loss)	22,945	41,534	59,198	63,306
Comprehensive income (loss) attributable to Pentair, Inc.	22,945	41,534	59,198	63,306
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net sales	392,347	398,634	778,524	740,212
Cost of goods sold	287,437	297,830	564,599	549,560
Gross profit	104,910	100,804	213,925	190,652
Selling, general and administrative	75,746	68,329	145,815	121,644
Research and development	9,688	8,938	19,612	16,044
Operating (loss) income	19,476	23,537	48,498	52,964
Earnings from investment in subsidiaries	600		(364)
Other (income) expense:
Equity income of unconsolidated subsidiaries		(65)	(141)	(124)
Net interest (income) expense	5,454	3,142	11,073	1,361
Income before income taxes and noncontrolling interest	13,422	20,460	37,930	51,727
Provision for income taxes	(966)	1,623	3,300	10,651
Net income before noncontrolling interest	14,388	18,837	34,630	41,076
Noncontrolling interest	1,655	1,425	2,995	2,918
Net income attributable to Pentair, Inc.	12,733	17,412	31,635	38,158
Comprehensive income (loss)	(42,332)	29,491	16,435	67,508
Less: Comprehensive income attributable to noncontrolling interest	(223)	2,216	2,020	5,621
Comprehensive income (loss) attributable to Pentair, Inc.	(42,109)	27,275	14,415	61,887
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net sales	(79,682)	(74,854)	(165,750)	(141,213)
Cost of goods sold	(79,695)	(74,661)	(165,457)	(140,738)
Gross profit	13	(193)	(293)	(475)
Selling, general and administrative	13	(193)	(293)	(475)
Earnings from investment in subsidiaries	62,126	53,988	117,281	91,295
Other (income) expense:
Income before income taxes and noncontrolling interest	(62,126)	(53,988)	(117,281)	(91,295)
Net income before noncontrolling interest	(62,126)	(53,988)	(117,281)	(91,295)
Net income attributable to Pentair, Inc.	(62,126)	(53,988)	(117,281)	(91,295)
Comprehensive income (loss)	19,164	(68,809)	(73,613)	(125,193)
Comprehensive income (loss) attributable to Pentair, Inc.	$ 19,164	$ (68,809)	$ (73,613)	$ (125,193)