SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND PRACTICES - Additional Information (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2017 USD ($) employee country segment customer Location	Dec. 31, 2016 USD ($)	Jan. 01, 2017 USD ($)	Dec. 01, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Accounting Policies [Abstract]
Number of operating segments | segment	3
Number of locations in which company operates (more than) | Location	220
Number of countries in which the company operates | country	20
Number of employees (more than) | employee	7,400
Significant Accounting Policies [Line Items]
Cash and cash equivalents	$ 23,740,000	$ 46,216,000			$ 88,309,000	$ 44,825,000
Goodwill impairment		0
Discounted cash flow, forecast period	5 years
Market capitalization in excess of consolidated net assets				$ 437,000,000
Market capitalization in excess of consolidated net assets, percentage				80.00%
Goodwill	$ 356,347,000	355,786,000
Workers compensation our self-insured retention	1,000,000.0
Automobile liability self-insured retention	500,000
General liability claims we have an effective self-insured retention	3,000,000.0
Medical claims, our self-insured retention	350,000
Environmental liability claims, our self-insured retention	1,000,000
Unbilled revenues	$ 84,891,000	39,719,000
Sales Revenue, Net | Customer Concentration Risk
Significant Accounting Policies [Line Items]
Number of customers accounted for more than specified percentage of consolidated revenues | customer	0
Europe and Asia
Significant Accounting Policies [Line Items]
Cash and cash equivalents	$ 8,600,000	$ 14,000,000
ASU 2016-09
Significant Accounting Policies [Line Items]
Cumulative-effect adjustment to opening balance of retained earnings			$ 1,000,000