CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY/(DEFICIT) - USD ($) $ in Millions	Total	Common Stock	Preferred Stock	Preferred Stock	Preferred Stock Preferred Stock	Common Stock	Common Stock Common Stock	Additional Paid-in Capital	Additional Paid-in Capital Common Stock	Additional Paid-in Capital Preferred Stock	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive (Loss)/Income
Beginning Balance at Sep. 30, 2017	$ 85.1					$ 0.6		$ 196.7			$ 198.7	$ (72.1)	$ (238.8)
Beginning Balance (in shares) at Sep. 30, 2017						60,709,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss)/earnings	60.4										60.4
Share based payments	6.7							6.7
Activity under stock plans	(1.8)							(4.8)			(0.8)	3.8
Activity under stock plans (in shares)						91,000
Dividends to shareholders ($0.30 per share)	(18.7)										(18.7)
Other comprehensive loss	11.1												11.1
Net (loss)/earnings from continuing operations	68.2
Loss from discontinued operations, net of tax	0.0
Common stock purchased	(50.0)											(50.0)
Common stock purchased (in shares)						(1,126,000)
Ending Balance at Mar. 31, 2018	$ 44.7					$ 0.6		205.4			190.5	(117.7)	(234.1)
Ending Balance (in shares) at Mar. 31, 2018						59,686,000
Dividends per common share (in dollars per share)	$ 0.29
Beginning Balance at Dec. 31, 2017	$ 33.6					$ 0.6		198.6			180.4	(118.3)	(227.7)
Beginning Balance (in shares) at Dec. 31, 2017						59,674,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss)/earnings	7.8										7.8
Share based payments	7.3							7.3
Activity under stock plans	0.1							(0.5)			0.0	0.6
Activity under stock plans (in shares)						12,000
Dividends to shareholders ($0.30 per share)	(17.8)										(17.8)
Other comprehensive loss	13.7												13.7
Net (loss)/earnings from continuing operations	7.8
Loss from discontinued operations, net of tax	0.0
Ending Balance at Mar. 31, 2018	44.7					$ 0.6		205.4			190.5	(117.7)	(234.1)
Ending Balance (in shares) at Mar. 31, 2018						59,686,000
Beginning Balance at Sep. 30, 2018	24.5					$ 0.6		217.8			177.3	(129.4)	(241.8)
Beginning Balance (in shares) at Sep. 30, 2018						59,608,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss)/earnings	70.8										70.8
Share based payments	6.5							6.5
Activity under stock plans	(7.1)							(16.1)			(3.6)	12.6
Activity under stock plans (in shares)						290,000
Dividends to shareholders ($0.30 per share)	(18.4)										(18.4)
Other comprehensive loss	(5.9)												(5.9)
Net (loss)/earnings from continuing operations	8.5
Loss from discontinued operations, net of tax	(11.0)
Ending Balance at Mar. 31, 2019	$ 645.3					$ 0.7		860.5			127.9	(116.3)	(227.5)
Ending Balance (in shares) at Mar. 31, 2019						69,875,000
Dividends per common share (in dollars per share)	$ 0.30
Preferred stock dividend declared (in dollars per share)	$ 1.83
Beginning Balance at Dec. 31, 2018	$ 70.4					$ 0.6		208.2			226.1	(116.8)	(247.7)
Beginning Balance (in shares) at Dec. 31, 2018						59,898,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share based payments	7.6							7.6
Activity under stock plans	0.0							(0.5)				0.5
Activity under stock plans (in shares)						11,000
Dividends to shareholders ($0.30 per share)	(21.6)										(21.6)
Dividends to common shareholders ($0.30 per share)	(3.3)										(3.3)
Other comprehensive loss	20.2												20.2
Net (loss)/earnings from continuing operations	(62.3)										(62.3)
Loss from discontinued operations, net of tax	$ (11.0)										(11.0)
Issuance of stock		$ 445.8	$ 199.5				$ 0.1		$ 445.7	$ 199.5
Issuance of stock (in shares)					2,156,000		9,966,000
Common stock purchased (in shares)	(1,126,379)
Ending Balance at Mar. 31, 2019	$ 645.3					$ 0.7		$ 860.5			$ 127.9	$ (116.3)	$ (227.5)
Ending Balance (in shares) at Mar. 31, 2019						69,875,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Preferred Stock, Shares Outstanding				2,156,000