Condensed Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2018
Business Acquisition [Line Items]
Common stock repurchase not settled (in shares)		200,000
Common Stock Repurchase not settled, Value		$ 8.8
Forfeiture of certain shares to satisfy exercise costs and the recipients' income tax obligations related to stock options exercised and restricted stock vested	$ (1.8)
PMLJV
Business Acquisition [Line Items]
Percentage of membership interest in joint venture by other party	10.00%
Common Stock
Business Acquisition [Line Items]
Forfeiture of certain shares to satisfy exercise costs and the recipients' income tax obligations related to stock options exercised and restricted stock vested (in shares)	(55,526)