Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Jan. 01, 2023	Jan. 02, 2022
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning stockholders’ equity	$ 8,169.2	$ 7,622.0	$ 3,228.6
Other comprehensive income (loss) before reclassifications	94.4	(326.9)
Amounts reclassified from AOCI	(2.0)	30.4
Net other comprehensive income (loss)	92.4	(296.5)	0.1
Ending stockholders' equity	9,221.2	8,169.2	7,622.0
Gain (loss) on cash flow hedges:
Gain (loss) recognized in income on derivatives	3,196.1	3,128.3	2,772.9
Income tax impact	72.3	119.2	88.5
Net income (loss) attributable to Teledyne	885.7	788.6	445.3
Amortization of defined benefit pension and postretirement plan items:
Income tax impact	(72.3)	(119.2)	(88.5)
Amount reclassified from AOCI
Gain (loss) on cash flow hedges:
Net income (loss) attributable to Teledyne	5.9	42.1
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning stockholders’ equity	(472.3)	(129.0)
Other comprehensive income (loss) before reclassifications	79.6	(343.3)
Amounts reclassified from AOCI	0.0	0.0
Net other comprehensive income (loss)	79.6	(343.3)
Ending stockholders' equity	(392.7)	(472.3)	(129.0)
Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning stockholders’ equity	1.3	(3.4)
Other comprehensive income (loss) before reclassifications	14.8	16.4
Amounts reclassified from AOCI	(7.9)	(11.7)
Net other comprehensive income (loss)	6.9	4.7
Ending stockholders' equity	8.2	1.3	(3.4)
Cash Flow Hedges | Amount reclassified from AOCI
Gain (loss) on cash flow hedges:
Gain (loss) recognized in income on derivatives	(10.6)	(15.7)
Income tax impact	2.7	4.0
Net income (loss) attributable to Teledyne	(7.9)	(11.7)
Amortization of defined benefit pension and postretirement plan items:
Income tax impact	(2.7)	(4.0)
Pension and Postretirement Benefits
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning stockholders’ equity	(255.5)	(297.6)
Other comprehensive income (loss) before reclassifications	0.0	0.0
Amounts reclassified from AOCI	5.9	42.1
Net other comprehensive income (loss)	5.9	42.1
Ending stockholders' equity	(249.6)	(255.5)	(297.6)
Pension and Postretirement Benefits | Amount reclassified from AOCI
Gain (loss) on cash flow hedges:
Income tax impact	1.5	24.0
Amortization of defined benefit pension and postretirement plan items:
Total before tax	7.4	66.1
Income tax impact	(1.5)	(24.0)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning stockholders’ equity	(726.5)	(430.0)	(430.1)
Net other comprehensive income (loss)	92.4	(296.5)	0.1
Ending stockholders' equity	(634.1)	(726.5)	$ (430.0)
Amortization of prior service cost | Amount reclassified from AOCI
Amortization of defined benefit pension and postretirement plan items:
Total before tax	(1.7)	(1.8)
Amortization of net actuarial loss | Amount reclassified from AOCI
Amortization of defined benefit pension and postretirement plan items:
Total before tax	10.1	22.7
Pension adjustments | Amount reclassified from AOCI
Amortization of defined benefit pension and postretirement plan items:
Total before tax	$ (1.0)	$ 45.2