Stockholders' equity (Tables)

12 Months Ended

Dec. 31, 2020

Equity [Abstract]

Accumulated Other Comprehensive Income (Loss)

Accumulated other comprehensive income (loss) attributable to Unisys Corporation is as follows:

	Total		Translation Adjustments		Postretirement Plans
Balance at December 31, 2017	$	(3,815.8)	$	(817.0)	$	(2,998.8)
Reclassification pursuant to ASU No. 2018-02	(208.7)		—		(208.7)
Other comprehensive income before reclassifications	96.7		(79.7)		176.4
Amounts reclassified from accumulated other comprehensive income	(157.0)		—		(157.0)
Current period other comprehensive income	(269.0)		(79.7)		(189.3)
Balance at December 31, 2018	(4,084.8)		(896.7)		(3,188.1)
Other comprehensive income before reclassifications	136.8		23.8		113.0
Amounts reclassified from accumulated other comprehensive income	(140.6)		—		(140.6)
Current period other comprehensive income	(3.8)		23.8		(27.6)
Balance at December 31, 2019	(4,088.6)		(872.9)		(3,215.7)
Other comprehensive income before reclassifications	489.4		78.6		410.8
Amounts reclassified from accumulated other comprehensive income	(340.3)		(32.3)		(308.0)
Current period other comprehensive income	149.1		46.3		102.8
Balance at December 31, 2020	$	(3,939.5)	$	(826.6)	$	(3,112.9)

Amounts Reclassified Out of Accumulated Other Comprehensive Income (Loss)

Amounts reclassified out of accumulated other comprehensive loss are as follows:

Year ended December 31,	2020		2019		2018
Translation Adjustments:
Adjustment for substantial completion of liquidation of foreign subsidiaries(i)	$	(32.3)	$	—	$	—
Postretirement Plans:
Amortization of prior service cost(ii)	5.9		5.9		7.1
Amortization of actuarial losses(ii)	(177.3)		(149.7)		(165.9)
Settlement loss(ii)	(142.1)		(1.1)		(3.9)
Total before tax	(345.8)		(144.9)		(162.7)
Income tax benefit	5.5		4.3		5.7
Total reclassifications for the period	$	(340.3)	$	(140.6)	$	(157.0)

(i) Reported in other expense, net in the consolidated statements of income

(ii) Included in net periodic postretirement cost (see Note 17)

Changes in Common Stock and Treasury Stock

The following table summarizes the changes in shares of common stock and treasury stock:

	Common Stock	Treasury Stock
Balance at December 31, 2017	53.4	2.9
Stock-based compensation	0.8	0.2
Balance at December 31, 2018	54.2	3.1
Debt exchange	10.6	—
Stock-based compensation	1.1	0.4
Balance at December 31, 2019	65.9	3.5
Stock-based compensation	0.9	0.3
Balance at December 31, 2020	66.8	3.8