Share-Based Compensation - Restricted Stock Unit Activity (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	12 Months Ended
	Jan. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Time-based Restricted Stock Units
Units (In thousands)
Beginning balance (in shares)	563,224	563,224
Granted (in shares)		902,485
Vested (in shares)		(300,430)
Forfeited (in shares)		(93,320)
Ending balance (in shares)		1,071,959	563,224
Aggregate intrinsic value, nonvested		$ 35.1	$ 21.0
Shares vested, but not released (in shares)		615,643
Aggregate intrinsic value, shares vested but not released		$ 20.2
Total outstanding restricted stock units (in shares)		1,687,602
Aggregate intrinsic value, total outstanding restricted stock units		$ 55.3
Performance-Based Restricted Stock Units
Units (In thousands)
Beginning balance (in shares)	42,856	42,856
Granted (in shares)		0
Vested (in shares)		(14,286)
Forfeited (in shares)		(28,570)
Ending balance (in shares)		0	42,856
Aggregate intrinsic value, nonvested		$ 0.0	$ 1.6
Shares vested, but not released (in shares)		42,856
Aggregate intrinsic value, shares vested but not released		$ 1.4
Total outstanding restricted stock units (in shares)		42,856
Aggregate intrinsic value, total outstanding restricted stock units		$ 1.4
Market-Based Restricted Stock Units
Units (In thousands)
Beginning balance (in shares)	873,581	873,581
Granted (in shares)		108,781
Market-performance adjustment		266,531
Vested (in shares)	(799,591)	(800,087)
Forfeited (in shares)		(74,758)
Ending balance (in shares)		374,048	873,581
Aggregate intrinsic value, nonvested		$ 12.3	$ 42.6
Shares vested, but not released (in shares)		0
Aggregate intrinsic value, shares vested but not released		$ 0.0
Total outstanding restricted stock units (in shares)		374,048
Aggregate intrinsic value, total outstanding restricted stock units		$ 12.3
Measurement period (in years)		3 years
Market performance metric, vesting percent of target		150.00%
Former Director | Restricted Stock Units
Units (In thousands)
Vested (in shares)		(14,286)
Shares vested, but not released (in shares)		568,753
Vested awards, weighted average grant date fair value (in USD per share)		$ 9.38
Director | Time-based Restricted Stock Units
Units (In thousands)
Granted (in shares)			16,325	20,190
Director | Restricted Stock Units
Units (In thousands)
Granted (in shares)		6,616	8,517	18,267
Shares vested, but not released (in shares)		46,890
Vested awards, weighted average grant date fair value (in USD per share)		$ 8.42
Former Chief Executive Officer | Restricted Stock Units
Units (In thousands)
Shares vested, but not released (in shares)		42,856
Vested awards, weighted average grant date fair value (in USD per share)		$ 13.43