Shareholders' Equity - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands					1 Months Ended		3 Months Ended		6 Months Ended
	Jan. 15, 2022	Apr. 29, 2019	Apr. 15, 2019	Jan. 28, 2019	Jan. 31, 2019	Nov. 30, 2018	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018	Jul. 31, 2015
Class of Stock [Line Items]
Number of shares repurchased (shares)							1,126,379
Shares repurchased										$ 50,000
Average purchase price (in dollars per share)										$ 44.41
Dividend declared (in dollars per share)				$ 0.30		$ 0.30	$ 0.30	$ 0.29
Common stock dividends declared									$ 40,000	$ 36,500
Dividends paid									40,800	35,000
Common stock isued (in shares)					4,687,498
Net proceeds from issuance of common stock									205,300	0
Preferred stock issued (in shares)					2,156,250
Net proceeds from issuance of mandatory convertible preferred shares									$ 199,500	$ 0
Preferred stock, par value (in dollars per share)					$ 0.01
Liquidation preference (in dollars per share)					$ 100.00
Mandatory convertible preferred stock annual rate					7.50%
Preferred stock dividend declared (in dollars per share)				$ 1.8333			$ 1.83
Preferred stock dividends							$ 3,300
Payments for capped call transactions				$ 9,000
Minimum | Scenario, Forecast
Class of Stock [Line Items]
Conversion of preferred stock to common stock (in shares)	1,789,200
Maximum | Scenario, Forecast
Class of Stock [Line Items]
Conversion of preferred stock to common stock (in shares)	2,173,900
Over-Allotment Option
Class of Stock [Line Items]
Common stock isued (in shares)					611,412
Preferred stock issued (in shares)					281,250
Spectrum Auto Care Acquisition
Class of Stock [Line Items]
Newly-issued common stock in acquisition (in shares)				5,278,921
Fair value of equity consideration				$ 240,500
Opening stock price (in dollars per share)				$ 45.55
Percentage not transferable, limit				4.90%
Value of common stock in company acquired				$ 65,120
Subsequent Event
Class of Stock [Line Items]
Dividend declared (in dollars per share)		$ 0.30
Preferred stock dividend declared (in dollars per share)		$ 1.875
Preferred stock dividends			$ 3,900
Common Stock
Class of Stock [Line Items]
Number of shares authorized to be acquired (shares)											7,500,000
Number of shares repurchased (shares)										1,126,000