Shareholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions		9 Months Ended
	Oct. 15, 2019	Sep. 30, 2019	Oct. 26, 2018	Mar. 06, 2018
Dividends Payable [Line Items]
Quarterly cash dividend declared		$ 0.15
Dividend declared date		Sep. 16, 2019
Dividend record date		Sep. 30, 2019
Dividends paid		$ 17.7
Dividend paid date		Oct. 15, 2019
Equity Class Of Treasury Stock [Line Items]
Repurchase of common shares program authorized amount			$ 100.0	$ 250.0
Repurchase of common shares remaining authorized amount		$ 83.2
Subsequent Event [Member]
Dividends Payable [Line Items]
Dividends paid	$ 5.6