SEGMENT INFORMATION (Details) (USD $)	3 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Mar. 31, 2012
Segment Reporting Information [Line Items]
Total segment gross revenue	$ 362,608,000	$ 321,105,000
Total intrasegment gross revenue	379,000	7,000
Total consolidated gross revenue	362,608,000	321,105,000
Total earnings from unconsolidated affiliates, net of losses - equity method investments	1,989,000	5,993,000
Total consolidated operating income	39,993,000	36,405,000
Total depreciation and amortization	21,372,000	22,708,000
Total identifiable assets	2,740,379,000		2,740,363,000
Total investments in unconsolidated affiliates - equity method	194,287,000		198,710,000
Construction in progress within property and equipment	152,200,000		126,600,000
Gain Loss On Disposition Of Other Assets [Member]
Segment Reporting Information [Line Items]
Total consolidated operating income	(5,315,000)	1,416,000
Corporate And Other [Member]
Segment Reporting Information [Line Items]
Total segment gross revenue	7,510,000	7,389,000
Total intrasegment gross revenue	120,000	(444,000)
Total consolidated gross revenue	7,630,000	6,945,000
Total earnings from unconsolidated affiliates, net of losses - equity method investments	0	0
Total consolidated operating income	(13,070,000)	(17,509,000)
Total depreciation and amortization	884,000	759,000
Total identifiable assets	390,088,000		410,157,000
Total investments in unconsolidated affiliates - equity method	3,228,000		2,378,000
Intersegment Elimination [Member]
Segment Reporting Information [Line Items]
Total consolidated gross revenue	(379,000)	(7,000)
Europe [Member]
Segment Reporting Information [Line Items]
Total segment gross revenue	153,957,000	134,280,000
Total intrasegment gross revenue	63,000	258,000
Total consolidated gross revenue	154,020,000	134,538,000
Total earnings from unconsolidated affiliates, net of losses - equity method investments	2,006,000	2,858,000
Total consolidated operating income	21,876,000	23,249,000
Total depreciation and amortization	7,564,000	7,907,000
Total identifiable assets	850,131,000		779,160,000
Total investments in unconsolidated affiliates - equity method	6,889,000		11,410,000
West Africa [Member]
Segment Reporting Information [Line Items]
Total segment gross revenue	70,454,000	54,507,000
Total intrasegment gross revenue	0	0
Total consolidated gross revenue	70,454,000	54,507,000
Total consolidated operating income	16,131,000	11,231,000
Total depreciation and amortization	3,142,000	3,270,000
Total identifiable assets	384,242,000		376,903,000
North America [Member]
Segment Reporting Information [Line Items]
Total segment gross revenue	52,710,000	44,167,000
Total intrasegment gross revenue	196,000	75,000
Total consolidated gross revenue	52,906,000	44,242,000
Total consolidated operating income	6,475,000	1,584,000
Total depreciation and amortization	3,266,000	3,687,000
Total identifiable assets	290,428,000		276,074,000
Australia [Member]
Segment Reporting Information [Line Items]
Total segment gross revenue	44,502,000	45,295,000
Total intrasegment gross revenue	0	118,000
Total consolidated gross revenue	44,502,000	45,413,000
Total consolidated operating income	6,509,000	4,524,000
Total depreciation and amortization	2,483,000	3,122,000
Total identifiable assets	263,813,000		295,895,000
Other International [Member]
Segment Reporting Information [Line Items]
Total segment gross revenue	33,475,000	35,467,000
Total intrasegment gross revenue	0	0
Total consolidated gross revenue	33,475,000	35,467,000
Total earnings from unconsolidated affiliates, net of losses - equity method investments	(17,000)	3,135,000
Total consolidated operating income	7,387,000	11,910,000
Total depreciation and amortization	4,033,000	3,963,000
Total identifiable assets	561,677,000		602,174,000
Total investments in unconsolidated affiliates - equity method	$ 184,170,000		$ 184,922,000