ACCOUNTING POLICIES AND PRONOUNCEMENTS (Narrative) (Details) - USD ($)		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017	Jan. 01, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification out of AOCI to retained earnings	[1]	$ 1,148,000	$ 0
Decrease to accumulated other comprehensive income		797,000			$ 6,965,000
Cumulative effect of adjustment, accumulated deficit					(69,732,000)
Reclassification of cash used in operating activities		86,421,000	97,419,000
Reclassification of cash used in investing activities		99,881,000	85,031,000
Increase in restricted cash		0	0
Contract assets		$ 0			$ 0
Accounting Standard Update 2017-12 | New Accounting Pronouncement, Early Adoption, Effect
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease to accumulated other comprehensive income				$ 700,000
Cumulative effect of adjustment, accumulated deficit				$ 700,000
Accounting Standards Update 2016-18
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of cash used in operating activities			39,700,000
Reclassification of cash used in investing activities			2,500,000
Increase in restricted cash			$ 37,200,000

[1] The Company adopted Accounting Standards Update ("ASU") 2018-02, Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income, as of January 1, 2018. See Note 2 - Accounting Policies and Pronouncements for further discussion.