Schedule of Goodwill and Changes to Goodwill by Reportable Segment (Detail) - USD ($) $ in Thousands		3 Months Ended			12 Months Ended
		Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2013	Mar. 31, 2015		Mar. 31, 2014
Goodwill [Line Items]
Goodwill, Beginning Balance	[1]		$ 283,699		$ 283,699
Impairments		$ 283,699		$ 56,283	283,699	[1]	$ 56,283
Goodwill, Ending Balance	[1]						283,699
Americas
Goodwill [Line Items]
Goodwill, Beginning Balance			114,237		114,237
Impairments					114,237
Goodwill, Ending Balance							114,237
Sub-Saharan Africa/Europe
Goodwill [Line Items]
Goodwill, Beginning Balance			169,462		169,462
Goodwill acquired			$ 42,200
Impairments					$ 169,462
Goodwill, Ending Balance							$ 169,462

[1] The total carrying amount of goodwill at March 31, 2014 is net of accumulated impairment charges $30.9 million and $56.3 million related to the Middle East/North Africa and Asia/Pacific segments, respectively.