COMMITMENTS AND CONTINGENCIES (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	6 Months Ended	0 Months Ended	1 Months Ended
	Nov. 30, 2007 Lawsuit filed by CTL Minimum	Jun. 30, 2013 Pending litigation, adverse outcome	Jun. 17, 2013 Letter of credit sub-facility Amended Credit Facility	Oct. 31, 2012 Letter of credit sub-facility Amended Credit Facility	Jun. 30, 2013 Letter of credit sub-facility Amended Credit Facility	Oct. 29, 2012 Letter of credit sub-facility Amended Credit Facility
Commitments and contingencies
Letters of credit issued to the USAC			$ 29.8
Amount of pending awards of mobility fund grants			68.8
Maximum borrowing capacity			55.0			55.0
Commitment fee (as a percent)			1.75%	1.75%
Draw downs against issued letters of credit					0
Damages asserted	200.0
Period for which litigation proceedings and other disputes have not been the subject of discussions or other significant activity		5 years
Accrued contingent liability		$ 5.0