Acquisitions (Details) - USD ($) $ in Millions				3 Months Ended	6 Months Ended		7 Months Ended	12 Months Ended
	Nov. 20, 2019	Apr. 01, 2019	Jan. 11, 2019	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Dec. 31, 2019
Recognized amounts of identifiable assets acquired and liabilities assumed:
Goodwill					$ 1,708.3		$ 1,708.3	$ 1,716.3
Other Long-term Assets
Recognized amounts of identifiable assets acquired and liabilities assumed:
Indemnification asset			$ 5.2
Providien, LLC
Acquisitions
Total cash consideration transferred	$ 332.1						331.3
Recognized amounts of identifiable assets acquired and liabilities assumed:
Cash and cash equivalents	3.4				3.4		3.4
Receivables, net	9.8				9.8		9.8
Inventories, net	2.7				2.7		2.7
Contract assets	29.1				29.1		29.1
Prepaid expenses and other current assets	2.3				2.3		2.3
Property, plant and equipment	12.9				12.9		12.9
Definite-lived intangible assets	135.4				132.7		132.7
Other long-term assets	7.1				6.8		6.8
Accounts payable	(6.0)				(6.0)		(6.0)
Income tax payable	(0.7)				(0.7)		(0.7)
Accrued and other current liabilities	(7.0)				(7.0)		(7.0)
Other long-term liabilities	(8.1)				(7.6)		(7.6)
Deferred income taxes	(27.1)				(20.2)		(20.2)
Total identifiable net assets	153.8				158.2		158.2
Receivables not expected to be collected	0.1
Goodwill deductible for tax purposes	66.5
Providien, LLC | Adjustment
Acquisitions
Total cash consideration transferred							(0.8)
Recognized amounts of identifiable assets acquired and liabilities assumed:
Definite-lived intangible assets					(2.7)		(2.7)
Other long-term assets					(0.3)		(0.3)
Other long-term liabilities					0.5		0.5
Deferred income taxes					6.9		6.9
Total identifiable net assets					4.4		4.4
Providien, LLC | Customer relationships
Recognized amounts of identifiable assets acquired and liabilities assumed:
Finite-lived intangible assets acquired	$ 108.7
Providien, LLC | Customer relationships | Minimum
Recognized amounts of identifiable assets acquired and liabilities assumed:
Useful life of finite lived intangible assets	13 years
Providien, LLC | Customer relationships | Maximum
Recognized amounts of identifiable assets acquired and liabilities assumed:
Useful life of finite lived intangible assets	37 years
Providien, LLC | Acquired Technology
Recognized amounts of identifiable assets acquired and liabilities assumed:
Finite-lived intangible assets acquired	$ 19.5
Providien, LLC | Acquired Technology | Minimum
Recognized amounts of identifiable assets acquired and liabilities assumed:
Useful life of finite lived intangible assets	6 years
Providien, LLC | Acquired Technology | Maximum
Recognized amounts of identifiable assets acquired and liabilities assumed:
Useful life of finite lived intangible assets	11 years
Providien, LLC | Trade names
Recognized amounts of identifiable assets acquired and liabilities assumed:
Finite-lived intangible assets acquired	$ 4.4
Providien, LLC | Trade names | Minimum
Recognized amounts of identifiable assets acquired and liabilities assumed:
Useful life of finite lived intangible assets	2 years
Providien, LLC | Trade names | Maximum
Recognized amounts of identifiable assets acquired and liabilities assumed:
Useful life of finite lived intangible assets	5 years
Petersen Aluminum Corporation
Acquisitions
Percentage of ownership interest acquired			100.00%
Total cash consideration transferred			$ 207.2					207.2
Recognized amounts of identifiable assets acquired and liabilities assumed:
Cash and cash equivalents			5.2					5.2
Receivables, net			11.5					11.5
Inventories, net			39.5					39.2
Prepaid expenses and other current assets			2.1					2.1
Property, plant and equipment			17.8					17.8
Definite-lived intangible assets			109.3					110.1
Other long-term assets			9.5					9.5
Accounts payable			(5.9)					(5.9)
Income tax payable			1.7					1.7
Accrued and other current liabilities			(8.7)					(8.7)
Other long-term liabilities			(12.4)					(12.5)
Deferred income taxes			(25.4)					(25.6)
Total identifiable net assets			144.2					144.4
Goodwill			63.0					62.8
Gross contractual accounts receivable acquired			11.6
Receivables not expected to be collected			0.1
Goodwill deductible for tax purposes								0.0
Indemnification asset			5.2
Release of indemnification asset related to escrow expirations					3.0
Petersen Aluminum Corporation | Adjustment
Recognized amounts of identifiable assets acquired and liabilities assumed:
Inventories, net								(0.3)
Definite-lived intangible assets								0.8
Other long-term liabilities								(0.1)
Deferred income taxes								(0.2)
Total identifiable net assets								0.2
Goodwill								(0.2)
Petersen Aluminum Corporation | Customer relationships
Recognized amounts of identifiable assets acquired and liabilities assumed:
Finite-lived intangible assets acquired			$ 79.7
Useful life of finite lived intangible assets			11 years
Petersen Aluminum Corporation | Acquired Technology
Recognized amounts of identifiable assets acquired and liabilities assumed:
Finite-lived intangible assets acquired			$ 2.5
Useful life of finite lived intangible assets			10 years
Petersen Aluminum Corporation | Trade names
Recognized amounts of identifiable assets acquired and liabilities assumed:
Finite-lived intangible assets acquired			$ 27.9
Useful life of finite lived intangible assets			17 years
MicroConnex Corporation
Acquisitions
Percentage of ownership interest acquired		100.00%
Total cash consideration transferred		$ 46.2
Recognized amounts of identifiable assets acquired and liabilities assumed:
Cash and cash equivalents		0.8
Carlisle Interconnect Technologies
Recognized amounts of identifiable assets acquired and liabilities assumed:
Goodwill					827.5		827.5	835.2
Carlisle Interconnect Technologies | Providien, LLC
Recognized amounts of identifiable assets acquired and liabilities assumed:
Goodwill	$ 178.3				173.1		173.1
Carlisle Interconnect Technologies | Providien, LLC | Adjustment
Recognized amounts of identifiable assets acquired and liabilities assumed:
Goodwill					(5.2)		(5.2)
Carlisle Interconnect Technologies | MicroConnex Corporation
Acquisitions
Contribution to net sales since acquisition				$ 3.0
Contribution to operating income since acquisition				(0.6)
Recognized amounts of identifiable assets acquired and liabilities assumed:
Receivables, net		3.4
Inventories, net		0.9
Definite-lived intangible assets		27.4
Accounts payable		(0.6)
Deferred income taxes		(7.0)
Goodwill		15.2
Goodwill deductible for tax purposes		$ 0.0
Carlisle Interconnect Technologies | MicroConnex Corporation | Customer relationships
Recognized amounts of identifiable assets acquired and liabilities assumed:
Useful life of finite lived intangible assets		12 years
Carlisle Interconnect Technologies | MicroConnex Corporation | Acquired Technology
Recognized amounts of identifiable assets acquired and liabilities assumed:
Useful life of finite lived intangible assets		5 years
Carlisle Interconnect Technologies | MicroConnex Corporation | Trade names
Recognized amounts of identifiable assets acquired and liabilities assumed:
Useful life of finite lived intangible assets		17 years
Carlisle Construction Materials
Recognized amounts of identifiable assets acquired and liabilities assumed:
Goodwill					$ 598.2		$ 598.2	$ 597.1
Carlisle Construction Materials | Petersen Aluminum Corporation
Acquisitions
Contribution to net sales since acquisition				48.3		$ 83.8
Contribution to operating income since acquisition				$ 3.7		$ 3.6