Acquisitions and Divestitures - Purchase Price (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended			9 Months Ended
	Sep. 28, 2013	Sep. 28, 2012 Tyco Flow Control Business [Member]		Sep. 28, 2013 Cash Paid In Settlement Of Working Capital Adjustment [Member]	Sep. 28, 2013 Value Of Replacement Equity Based Awards [Member]
Business Acquisition [Line Items]
Purchase Price Fair Value Adjustments	$ 93.0			$ 84.4	$ 8.6
Value of common shares issued to Tyco shareholders		4,811.4	[1]
Value of replacement equity-based awards to holders of Tyco equity-based awards		119.8	[2]
Cash paid to Tyco shareholders in lieu of fractional common shares		0.5	[3]
Cash paid to Tyco in settlement of the working capital and net indebtedness calculation		84.4
Total purchase price		$ 5,016.1

[1] Equals 110.9 million Pentair Ltd. shares distributed to Tyco shareholders multiplied by the Merger date share price of $43.39.

[2] In accordance with applicable accounting guidance, the fair value of replacement equity-based awards attributable to pre-combination service is recorded as part of the consideration transferred in the Merger, while the fair value of replacement equity-based awards attributable to post-combination service is recorded separately from the business combination and recognized as compensation cost in the post-acquisition period over the remaining service period. The fair value of our equivalent stock options was estimated using the Black-Scholes valuation model utilizing various assumptions.

[3] Equals cash paid to Tyco shareholders in lieu of less than 0.1 million Pentair Ltd. fractional shares multiplied by the Merger date share price of $43.39.