Accumulated Other Comprehensive Income (Tables)

12 Months Ended

Dec. 31, 2020

Equity [Abstract]

Reclassification of Accumulated Other Comprehensive Income (Loss)

The changes in accumulated other comprehensive income by component are summarized below:

($ in millions)	Foreign currency translation adjustments		Other adjustments (b)			Total
Balance, January 1, 2018	$	164.8	$	(6.0)		$	158.8
Other comprehensive income (loss) before reclassifications:
Increase (decrease)	(33.5)		0.5			(33.0)
Other comprehensive income (loss) before reclassifications, net of income taxes	(33.5)		0.5			(33.0)
Amounts reclassified from accumulated other comprehensive income (loss):
Increase (decrease)	—		0.5		(a)	0.5
Amounts reclassified from accumulated other comprehensive income (loss), net of income taxes:	—		0.5			0.5
Net current period other comprehensive income (loss):	(33.5)		1.0			(32.5)
Balance, December 31, 2018	$	131.3	$	(5.0)		$	126.3
Other comprehensive income (loss) before reclassifications:
Increase (decrease)	22.4		(0.4)			22.0
Other comprehensive income (loss) before reclassifications, net of income taxes	22.4		(0.4)			22.0
Amounts reclassified from accumulated other comprehensive income (loss):
Increase (decrease)	—		0.4		(a)	0.4
Amounts reclassified from accumulated other comprehensive income (loss), net of income taxes	—		0.4			0.4
Net current period other comprehensive income (loss)	22.4		—			22.4
Balance, December 31, 2019	$	153.7	$	(5.0)		$	148.7
Other comprehensive income (loss) before reclassifications:
Increase (decrease)	44.6		—			44.6
Other comprehensive income (loss) before reclassifications, net of income taxes	44.6		—			44.6
Amounts reclassified from accumulated other comprehensive income (loss):
Increase (decrease)	—		0.5		(a)	0.5
Amounts reclassified from accumulated other comprehensive income (loss), net of income taxes:	—		0.5			0.5
Net current period other comprehensive income (loss)	44.6		0.5			45.1
Balance, December 31, 2020	$	198.3	$	(4.5)		$	193.8
(a) This accumulated other comprehensive income (loss) component is included in the computation of net periodic pension cost.
(b) Includes balances relating to defined benefit plans, supplemental executive retirement plans and other postretirement employee benefit plans.