Stock-Based Compensation - Stock Option Activity (Details) - $ / shares	3 Months Ended	9 Months Ended		12 Months Ended
	Mar. 31, 2020	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Number of Shares
Options outstanding, beginning balance (in shares)	1,342,000	1,342,000
Options granted (in shares)		0	0
Options exercised (in shares)		(59,000)
Options cancelled/forfeited (in shares)		(55,000)
Options outstanding, ending balance (in shares)		1,228,000		1,342,000
Weighted Average Exercise Price per Share
Options outstanding, weighted average exercise price, beginning balance (in dollars per share)	$ 11.84	$ 11.84
Options granted, weighted average exercise price (in dollars per share)		0
Options exercised, weighted average exercise price (in dollars per share)		6.87
Options cancelled/forfeited, weighted average exercise price (in dollars per share)		23.76
Options outstanding, weighted average exercise price, ending balance (in dollars per share)		$ 11.53		$ 11.84
Weighted average remaining contractual life, in years	5 years 10 months 24 days	5 years 1 month 6 days
PSOs | 2017 Performance Metric, Targeted Free Cash Flow Performance Metric
Weighted Average Exercise Price per Share
Share-based compensation options vested (in shares)		77,000		40,000
Percent of achievement of award target performance metric		95.00%		115.00%