CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Millions	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Non-controlling Interests [Member]	Total	Cumulative Effect, Period of Adoption, Adjustment [Member] Common Stock [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Additional Paid-in Capital [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Retained Earnings [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Accumulated Other Comprehensive Income (Loss) [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Treasury Stock [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Non-controlling Interests [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member]
Balance at Dec. 31, 2017	$ 4.9	$ 422.7	$ 1,607.2	$ (186.1)	$ (597.0)	$ 27.4	$ 1,279.1
Net income	0.0	0.0	169.0	0.0	0.0	4.2	173.2
Other comprehensive income (loss)	0.0	0.0	0.0	(47.6)	0.0	(1.8)	(49.4)
Dividends declared	0.0	0.0	(7.1)	0.0	0.0	0.0	(7.1)
Dividends paid to non-controlling interests	0.0	0.0	0.0	0.0	0.0	(1.8)	(1.8)
Acquisition of non-controlling interest	0.0	0.0	0.0	0.0	0.0	0.1	0.1
Capital contribution from non-controlling interests	0.0	0.0	0.0	0.0	0.0	3.7	3.7
Issuance of shares pursuant to employee stock compensation plans	0.0	3.0	0.0	0.0	0.0	0.0	3.0
Purchase of common stock for treasury	0.0	0.0	0.0	0.0	(21.7)	0.0	(21.7)
Stock-based compensation	0.0	6.2	0.0	0.0	0.0	0.0	6.2
Balance at Dec. 31, 2018	4.9	431.9	1,769.1	(233.7)	(618.7)	31.8	1,385.3
Balance (ASU 2018-02 [Member]) at Dec. 31, 2018								$ 0.0	$ 0.0	$ 10.9	$ (10.9)	$ 0.0	$ 0.0	$ 0.0
Net income	0.0	0.0	132.7	0.0	0.0	3.7	136.4
Other comprehensive income (loss)	0.0	0.0	0.0	(45.8)	0.0	0.0	(45.8)
Dividends declared	0.0	0.0	(7.0)	0.0	0.0	0.0	(7.0)
Dividends paid to non-controlling interests	0.0	0.0	0.0	0.0	0.0	(4.2)	(4.2)
Capital contribution from non-controlling interests	0.0	0.0	0.0	0.0	0.0	0.6	0.6
Issuance of shares pursuant to employee stock compensation plans	0.0	2.2	0.0	0.0	0.0	0.0	2.2
Purchase of common stock for treasury	0.0	0.0	0.0	0.0	(41.0)	0.0	(41.0)
Stock-based compensation	0.0	8.1	0.0	0.0	0.0	0.0	8.1
Balance at Dec. 31, 2019	4.9	442.2	1,905.7	(290.4)	(659.7)	31.9	1,434.6
Net income	0.0	0.0	112.4	0.0	0.0	3.4	115.8
Other comprehensive income (loss)	0.0	0.0	0.0	(17.9)	0.0	1.6	(16.3)
Dividends declared	0.0	0.0	(6.8)	0.0	0.0	0.0	(6.8)
Dividends paid to non-controlling interests	0.0	0.0	0.0	0.0	0.0	(0.7)	(0.7)
Capital contribution from non-controlling interests	0.0	0.0	0.0	0.0	0.0	1.7	1.7
Issuance of shares pursuant to employee stock compensation plans	0.0	3.2	0.0	0.0	0.0	0.0	3.2
Purchase of common stock for treasury	0.0	0.0	0.0	0.0	(40.7)	0.0	(40.7)
Stock-based compensation	0.0	10.2	0.0	0.0	0.0	0.0	10.2
Conversion of RSU's for tax withholding	0.0	(2.3)	0.0	0.0	0.0	0.0	(2.3)
Balance at Dec. 31, 2020	$ 4.9	$ 453.3	$ 2,011.3	$ (308.3)	$ (700.4)	$ 37.9	$ 1,498.7