SHARE-BASED COMPENSATION - Summary of Transactions Involving Stock Options (Details) - $ / shares shares in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
No. of Options
Shares under option, beginning of period	376	691
Changes during the period:
Granted (in shares)	0	0
Assumed - Furmanite acquisition (in shares)	132	0
Exercised (in shares)	(64)	(81)
Cancelled (in shares)	(2)	0
Expired (in shares)	(5)	0
Shares under option, end of period	437	610
Exercisable at end of period (in shares)	419	610
Weighted Average Exercise Price
Shares under option, beginning of period (in usd per share)	$ 25.71	$ 21.26
Changes during the period:
Granted (in usd per share)	0.00	0.00
Assumed - Furmanite acquisition (in usd per share)	33.20	0.00
Exercised (in usd per share)	15.67	12.80
Cancelled (in usd per share)	50.10	0.00
Expired (in usd per share)	30.33	0.00
Shares under option, end of period (in usd per share)	29.26	22.39
Exercisable at end of period (in usd per share)	$ 28.92	$ 22.39