COMMITMENTS AND CONTINGENCIES - Lease Obligations (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	9 Months Ended	12 Months Ended
	Feb. 28, 2013 Lease_Renewal	Sep. 30, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Leased Assets [Line Items]
Number of renewal options available under operating lease arrangement	5
Operating leases renewal term	5 years
Total lease payments		$ 1.8	$ 2.4	$ 2.1
Lease expense paid by parent company		0	0.7	1.0
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2015		4.3
2016		3.9
2017		4.0
2018		2.9
2019		2.1
2020 and thereafter		9.1
Company's headquarters
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Payments associated with leasing of Company's headquarters		$ 11.0