Consolidated Statements of Changes in Shareholders' Equity (USD $) In Thousands, except Share data	Total	Common shares	Additional paid-in capital	Retained earnings	Accumulated other comprehensive income (loss)	Total Pentair, Inc.	Noncontrolling interest	Comprehensive income (loss) attributable to Pentair, Inc.
Balance at Dec. 31, 2008	$ 2,020,069	$ 16,379	$ 451,241	$ 1,457,676	$ (26,615)	$ 1,898,681	$ 121,388
Balance (in shares) at Dec. 31, 2008		98,276,919
Net income	116,200			115,493		115,493	707	115,493
Change in cumulative translation adjustment	35,528				43,371	43,371	(7,843)	43,371
Adjustment in retirement liability, net of $(26,650) in 2011, $(8,159) in 2010 and $164 in 2009 tax	256				256	256		256
Changes in market value of derivative financial instruments, net of $ 2,884 in 2011, $229 in 2010 and ($2,323) in 2009 tax	3,585				3,585	3,585		3,585
Comprehensive income (loss)								162,705
Cash dividends-$0.80, in 2011, $0.76 in 2010 and $0.72 in 2009 per common share	(70,927)			(70,927)		(70,927)
Tax benefit of stock compensation	1,025		1,025			1,025
Exercise of stock options, net of 182,270 in 2011, 27,177 in 2010 and 124,613 in 2009 shares tendered for payment (in shares)		433,533
Exercise of stock options, net of 182,270 in 2011, 27,177 in 2010 and 124,613 in 2009 shares tendered for payment	7,711	72	7,639			7,711
Issuance of restricted shares, net of cancellations (in shares)		24,531
Issuance of restricted shares, net of cancellations	520	4	516			520
Amortization of restricted shares	7,190		7,190			7,190
Shares surrendered by employees to pay taxes (in shares)		(79,477)
Shares surrendered by employees to pay taxes	(1,880)	(13)	(1,867)			(1,880)
Stock compensation	7,063		7,063			7,063
Balance at Dec. 31, 2009	2,126,340	16,442	472,807	1,502,242	20,597	2,012,088	114,252
Balance (in shares) at Dec. 31, 2009		98,655,506
Net income	202,321			197,828		197,828	4,493	197,828
Change in cumulative translation adjustment	(32,706)				(30,487)	(30,487)	(2,219)	(30,487)
Adjustment in retirement liability, net of $(26,650) in 2011, $(8,159) in 2010 and $164 in 2009 tax	(12,762)				(12,762)	(12,762)		(12,762)
Changes in market value of derivative financial instruments, net of $ 2,884 in 2011, $229 in 2010 and ($2,323) in 2009 tax	310				310	310		310
Comprehensive income (loss)								154,889
Cash dividends-$0.80, in 2011, $0.76 in 2010 and $0.72 in 2009 per common share	(75,465)			(75,465)		(75,465)
Tax benefit of stock compensation	2,171		2,171			2,171
Distribution to noncontrolling interest	(4,647)						(4,647)
Share repurchase (in shares)		(726,777)
Share repurchase	(24,712)	(121)	(24,591)			(24,712)
Exercise of stock options, net of 182,270 in 2011, 27,177 in 2010 and 124,613 in 2009 shares tendered for payment (in shares)		651,331
Exercise of stock options, net of 182,270 in 2011, 27,177 in 2010 and 124,613 in 2009 shares tendered for payment	14,926	109	14,817			14,926
Issuance of restricted shares, net of cancellations (in shares)		(4,122)
Issuance of restricted shares, net of cancellations	706	(1)	707			706
Amortization of restricted shares	3,538		3,538			3,538
Shares surrendered by employees to pay taxes (in shares)		(166,746)
Shares surrendered by employees to pay taxes	(5,691)	(28)	(5,663)			(5,691)
Stock compensation	10,703		10,703			10,703
Balance at Dec. 31, 2010	2,205,032	16,401	474,489	1,624,605	(22,342)	2,093,153	111,879
Balance (in shares) at Dec. 31, 2010		98,409,192
Net income	38,521			34,222		34,222	4,299	34,222
Change in cumulative translation adjustment	(93,706)				(91,591)	(91,591)	(2,115)	(91,591)
Adjustment in retirement liability, net of $(26,650) in 2011, $(8,159) in 2010 and $164 in 2009 tax	(41,683)				(41,683)	(41,683)		(41,683)
Changes in market value of derivative financial instruments, net of $ 2,884 in 2011, $229 in 2010 and ($2,323) in 2009 tax	4,375				4,375	4,375		4,375
Comprehensive income (loss)								(94,677)
Cash dividends-$0.80, in 2011, $0.76 in 2010 and $0.72 in 2009 per common share	(79,537)			(79,537)		(79,537)
Tax benefit of stock compensation	3,868		3,868			3,868
Share repurchase (in shares)		(397,126)
Share repurchase	(12,785)	(66)	(12,719)			(12,785)
Exercise of stock options, net of 182,270 in 2011, 27,177 in 2010 and 124,613 in 2009 shares tendered for payment (in shares)		657,616
Exercise of stock options, net of 182,270 in 2011, 27,177 in 2010 and 124,613 in 2009 shares tendered for payment	14,708	110	14,598			14,708
Issuance of restricted shares, net of cancellations (in shares)		28,603
Issuance of restricted shares, net of cancellations	1,475	5	1,470			1,475
Amortization of restricted shares	1,006		1,006			1,006
Shares surrendered by employees to pay taxes (in shares)		(75,721)
Shares surrendered by employees to pay taxes	(2,798)	(13)	(2,785)			(2,798)
Stock compensation	8,916		8,916			8,916
Balance at Dec. 31, 2011	$ 2,047,392	$ 16,437	$ 488,843	$ 1,579,290	$ (151,241)	$ 1,933,329	$ 114,063
Balance (in shares) at Dec. 31, 2011		98,622,564