SIGNIFICANT ACCOUNTING POLICIES - Schedule of EPS (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Numerator for basic and diluted EPS – net loss available to common stockholders	$ (19.1)	$ (26.2)	$ (33.3)	$ (27.3)	$ (53.0)	$ (23.4)	$ (136.3)	$ (30.7)	$ (105.9)	$ (243.4)	$ (71.5)
Denominator for basic EPS – weighted average shares (in shares)	56,580,466	56,370,178	56,248,530	55,839,212	55,191,175	54,671,787	48,221,341	44,632,365	56,265,166	50,718,279	41,912,952
Effect of dilutive securities (in shares)									0	0	0
Denominator for diluted EPS – weighted average shares (in shares)	56,580,466	56,370,178	56,248,530	55,839,212	55,191,175	54,671,787	48,221,341	44,632,365	56,265,166	50,718,279	41,912,952
Loss per share: basic (in dollars per share)	$ (0.34)	$ (0.46)	$ (0.59)	$ (0.49)	$ (0.96)	$ (0.43)	$ (2.83)	$ (0.69)	$ (1.88)	$ (4.80)	$ (1.71)
Loss per share: diluted (in dollars per share)	$ (0.34)	$ (0.46)	$ (0.59)	$ (0.49)	$ (0.96)	$ (0.43)	$ (2.83)	$ (0.69)	$ (1.88)	$ (4.80)	$ (1.71)