Consolidated Statements of Operations and Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Net services revenue ($204.5 million and $583.7 million for the three and nine months ended September 30, 2019, respectively, and $155.3 million and $433.4 million for the three and nine months ended September 30, 2018, respectively, from related party)	$ 301.2	$ 250.4	$ 872.1	$ 605.6
Operating expenses:
Cost of services	241.9	219.3	725.2	547.9
Selling, general and administrative	28.3	29.6	76.6	69.1
Other expenses	7.4	7.3	26.9	22.9
Total operating expenses	277.6	256.2	828.7	639.9
Income (loss) from operations	23.6	(5.8)	43.4	(34.3)
Loss on debt extinguishment	0.0	0.0	(18.8)	0.0
Net interest (expense) income	(5.0)	(10.0)	(25.1)	(15.6)
Income (loss) before income tax provision (benefit)	18.6	(15.8)	(0.5)	(49.9)
Income tax provision (benefit)	9.4	(2.4)	(4.7)	(10.3)
Net income (loss)	$ 9.2	$ (13.4)	$ 4.2	$ (39.6)
Net income (loss) per common share:
Basic (in dollars per share)	$ 0.02	$ (0.17)	$ (0.10)	$ (0.50)
Diluted (in dollars per share)	$ 0.01	$ (0.17)	$ (0.10)	$ (0.50)
Weighted average shares used in calculating net income (loss) per common share:
Basic (in shares)	112,230,439	109,089,507	111,005,255	107,921,457
Diluted (in shares)	165,622,407	109,089,507	111,005,255	107,921,457
Consolidated statements of comprehensive income (loss)
Net income (loss)	$ 9.2	$ (13.4)	$ 4.2	$ (39.6)
Other comprehensive income (loss):
Net change on derivatives designated as cash flow hedges, net of tax	(0.5)	0.4	(0.2)	(0.2)
Foreign currency translation adjustments	(1.2)	(1.5)	(0.7)	(3.4)
Comprehensive income (loss)	7.5	(14.5)	3.3	(43.2)
Basic:
Net income (loss)	9.2	(13.4)	4.2	(39.6)
Less dividends on preferred shares	(5.3)	(4.8)	(15.4)	(14.2)
Less income allocated to preferred shareholders	(1.9)	0.0	0.0	0.0
Net income (loss) available/allocated to common shareholders - basic	2.0	(18.2)	(11.2)	(53.8)
Diluted:
Net income (loss)	9.2	(13.4)	4.2	(39.6)
Less dividends on preferred shares	(5.3)	(4.8)	(15.4)	(14.2)
Less income allocated to preferred shareholders	(1.5)	0.0	0.0	0.0
Net income (loss) available/allocated to common shareholders - diluted	$ 2.4	$ (18.2)	$ (11.2)	$ (53.8)