Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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Period Type:	duration

Basis of Presentation and Summary of Significant Accounting Policies - Share Repurchase Program (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Authorized amount repurchase of common stock				$ 50,000,000.0
Share repurchases		$ 3,300,000	$ 34,600,000
Completed common stock repurchase (in shares)	0
Remaining authorized repurchase amount	$ 12,000,000.0