BENEFIT PLANS: (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
BENEFIT PLANS:
Number of expatriate noncontributory defined benefit pension plans	2
Post retirement defined benefit plans
Defined benefit plan, net periodic benefit cost
Service cost	$ 0.3	$ 0.3
Interest cost	0.3	0.3
Expected return on plan assets	(0.9)	(0.9)
Amortization of net actuarial gain	(0.2)	(0.2)
Net periodic benefit costs	(0.5)	(0.5)
Post retirement defined benefit plans | Maximum
Defined benefit plan, net periodic benefit cost
Amortization of net loss (gain)	(0.1)	(0.1)
Post-retirement Health Care Plan
Defined benefit plan, net periodic benefit cost
Interest cost	0.3	0.4
Net periodic benefit costs	0.3	0.4
Post-retirement Health Care Plan | Maximum
Defined benefit plan, net periodic benefit cost
Amortization of net loss (gain)	(0.1)	(0.1)
Amortization of prior service cost (credit)	$ 0.1	$ 0.1