REVENUE RECOGNITION AND CONTRACTS - SPIG U.S. Loss Contracts (Details) $ in Millions	Mar. 31, 2019 USD ($) contract	Dec. 31, 2017 contract
Disaggregation of Revenue [Line Items]
Number of contracts in a loss position		6
SPIG segment
Disaggregation of Revenue [Line Items]
Number of contracts in a loss position	1
Percent complete	86.00%
Reserve for estimated contract losses | $	$ 2.0