Unaudited Condensed Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Millions	Total	Additional Paid-In Capital	Accumulated Earnings (Deficit)	Accumulated Other Comprehensive Income (Loss)	Class A	Class C
Beginning Balance at Dec. 31, 2019	$ 531.8	$ 557.5	$ (29.1)	$ 3.4
Beginning Balance (Shares) at Dec. 31, 2019					64,293,741	6,511,293
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based awards vested and distributed (shares)					51,603
Issue Director shares					6,903
Amortization of restricted stock units	2.2	2.2
Net income (loss)	(3.6)		(3.6)
Other comprehensive loss	(11.8)			(11.8)
Ending Balance at Mar. 31, 2020	518.6	559.7	(32.7)	(8.4)
Ending Balance (Shares) at Mar. 31, 2020					64,352,247	6,511,293
Beginning Balance at Dec. 31, 2019	531.8	557.5	(29.1)	3.4
Beginning Balance (Shares) at Dec. 31, 2019					64,293,741	6,511,293
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(12.1)				$ (11.0)	$ (1.1)
Other comprehensive loss	(10.0)
Ending Balance at Jun. 30, 2020	513.9	561.7	(41.2)	(6.6)
Ending Balance (Shares) at Jun. 30, 2020					64,556,459	6,511,293
Beginning Balance at Mar. 31, 2020	518.6	559.7	(32.7)	(8.4)
Beginning Balance (Shares) at Mar. 31, 2020					64,352,247	6,511,293
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based awards vested and distributed (shares)					143,048
Issue Director shares					61,164
Amortization of restricted stock units	2.0	2.0
Net income (loss)	(8.5)		(8.5)		$ (7.7)	$ (0.8)
Other comprehensive loss	1.8			1.8
Ending Balance at Jun. 30, 2020	513.9	561.7	(41.2)	(6.6)
Ending Balance (Shares) at Jun. 30, 2020					64,556,459	6,511,293
Beginning Balance at Dec. 31, 2020	$ 522.9	564.7	(52.5)	10.7
Beginning Balance (Shares) at Dec. 31, 2020	75,516,352				69,005,059	6,511,293
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based awards vested and distributed	$ (1.7)	(1.7)
Stock-based awards vested and distributed (shares)					332,718
Issue Director shares					5,584
Amortization of restricted stock units	2.7	2.7
Net income (loss)	6.3		6.3
Other comprehensive loss	(6.4)			(6.4)
Ending Balance at Mar. 31, 2021	523.8	565.7	(46.2)	4.3
Ending Balance (Shares) at Mar. 31, 2021					69,343,361	6,511,293
Beginning Balance at Dec. 31, 2020	$ 522.9	564.7	(52.5)	10.7
Beginning Balance (Shares) at Dec. 31, 2020	75,516,352				69,005,059	6,511,293
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 1.1				$ 1.0	$ 0.1
Other comprehensive loss	(3.8)
Ending Balance at Jun. 30, 2021	$ 629.3	673.8	(51.4)	6.9
Ending Balance (Shares) at Jun. 30, 2021	81,391,022				78,469,923	2,921,099
Beginning Balance at Mar. 31, 2021	$ 523.8	565.7	(46.2)	4.3
Beginning Balance (Shares) at Mar. 31, 2021					69,343,361	6,511,293
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholder conversion of class C to class A (Shares)					3,590,194	(3,590,194)
May 2021 equity offering	103.4	103.4
May 2021 equity offering (Shares)					5,250,000
Stock-based awards vested and distributed (shares)					202,414
Issue Director shares					83,954
Amortization of restricted stock units	4.7	4.7
Net income (loss)	(5.2)		(5.2)		$ (5.0)	$ (0.2)
Other comprehensive loss	2.6			2.6
Ending Balance at Jun. 30, 2021	$ 629.3	$ 673.8	$ (51.4)	$ 6.9
Ending Balance (Shares) at Jun. 30, 2021	81,391,022				78,469,923	2,921,099