Condensed Consolidated Statement Of Changes In Equity - USD ($) $ in Thousands		Total		Common And Treasury Stock [Member]	Treasury Stock [Member]	Number Of Shares, Net Of Treasury [Member]	Additional Paid In Capital [Member]	Retained Earnings [Member]		Accumulated Other Comprehensive Loss) [Member]		Parent [Member]	Noncontrolling Interest [Member]
Balance, Number of Shares at Jun. 30, 2018				81,577,217	(24,891,292)	56,685,925
Balance at Jun. 30, 2018		$ 736,897		$ 80	$ (286,951)		$ 276,201	$ 836,194	[1]	$ (184,538)	[1],[2]	$ 640,986	$ 95,911
Redeemable Common Stock, Balance at Jun. 30, 2018		107,672
Restricted stock granted, shares				148,000		148,000
Stock-based compensation charge (Note 14)		1,763					1,763					1,763
Reversal of stock-based compensation charge (Note 14)		(91)					(91)					(91)
Reversal of stock-based compensation charge (Note 14), shares				(18,000)		(18,000)
Stock based-compensation charge related to equity-accounted investment (Note 7)		77					77					77
Dividends paid to non-controlling interest		(4,085)											(4,085)
Disposal of DNI (Note 2)		(88,934)											(88,934)
Net (loss) income (Note 1)		(125,620)						(127,959)	[1]			(127,959)	2,339
Other comprehensive loss (Note 1 and Note 13)		$ (20,755)	[1]							(15,867)	[1]	(15,867)	(4,888)
Balance, Number of Shares at Mar. 31, 2019		56,815,925		81,707,217	(24,891,292)	56,815,925
Balance at Mar. 31, 2019		$ 499,252		$ 80	$ (286,951)		277,950	708,235	[1]	(200,405)	[1]	498,909	343
Redeemable Common Stock, Balance at Mar. 31, 2019		107,672
Balance, Number of Shares at Dec. 31, 2018				81,725,217	(24,891,292)	56,833,925
Balance at Dec. 31, 2018		650,904		$ 80	$ (286,951)		277,463	767,054	[1]	(198,374)	[1],[2]	559,272	91,632
Redeemable Common Stock, Balance at Dec. 31, 2018		107,672
Stock-based compensation charge (Note 14)		578					578					578
Reversal of stock-based compensation charge (Note 14)		(91)					(91)					(91)
Reversal of stock-based compensation charge (Note 14), shares				(18,000)		(18,000)
Dividends paid to non-controlling interest		(1,148)											(1,148)
Disposal of DNI (Note 2)		(88,934)											(88,934)
Net (loss) income (Note 1)		(59,547)						(58,819)	[1]			(58,819)	(728)
Other comprehensive loss (Note 1 and Note 13)		$ (2,510)	[1]							(2,031)	[1]	(2,031)	(479)
Balance, Number of Shares at Mar. 31, 2019		56,815,925		81,707,217	(24,891,292)	56,815,925
Balance at Mar. 31, 2019		$ 499,252		$ 80	$ (286,951)		277,950	708,235	[1]	(200,405)	[1]	498,909	343
Redeemable Common Stock, Balance at Mar. 31, 2019		107,672
Balance, Number of Shares at Jun. 30, 2019				81,459,717	(24,891,292)	56,568,425
Balance at Jun. 30, 2019		319,429	[1],[3]	$ 80	$ (286,951)		276,997	525,349	[2]	(196,046)	[2]	319,429	0
Redeemable Common Stock, Balance at Jun. 30, 2019	[1],[3]	107,672
Restricted stock granted, shares				568,000		568,000
Stock-based compensation charge (Note 14)		1,315					1,315					1,315
Reversal of stock-based compensation charge (Note 14)		(145)					(145)					(145)
Reversal of stock-based compensation charge (Note 14), shares				(17,500)		(17,500)
Stock based-compensation charge related to equity-accounted investment (Note 7)		71					71					71
Net (loss) income (Note 1)		(39,478)						(39,478)	[2]			(39,478)
Other comprehensive loss (Note 1 and Note 13)		$ (22,150)								(22,150)	[2]	(22,150)
Balance, Number of Shares at Mar. 31, 2020		57,118,925		82,010,217	(24,891,292)	57,118,925
Balance at Mar. 31, 2020		$ 259,042		$ 80	$ (286,951)		278,238	485,871	[2]	(218,196)	[2]	259,042	0
Redeemable Common Stock, Balance at Mar. 31, 2020		107,672
Balance, Number of Shares at Dec. 31, 2019				81,459,717	(24,891,292)	56,568,425
Balance at Dec. 31, 2019		320,560		$ 80	$ (286,951)		277,891	520,752	[2]	(191,212)	[2]	320,560	0
Redeemable Common Stock, Balance at Dec. 31, 2019		107,672
Restricted stock granted, shares				568,000		568,000
Stock-based compensation charge (Note 14)		492					492					492
Reversal of stock-based compensation charge (Note 14)		(145)					(145)					(145)
Reversal of stock-based compensation charge (Note 14), shares				(17,500)		(17,500)
Net (loss) income (Note 1)		(34,881)						(34,881)	[2]			(34,881)
Other comprehensive loss (Note 1 and Note 13)		$ (26,984)								(26,984)	[2]	(26,984)	0
Balance, Number of Shares at Mar. 31, 2020		57,118,925		82,010,217	(24,891,292)	57,118,925
Balance at Mar. 31, 2020		$ 259,042		$ 80	$ (286,951)		$ 278,238	$ 485,871	[2]	$ (218,196)	[2]	$ 259,042	$ 0
Redeemable Common Stock, Balance at Mar. 31, 2020		$ 107,672

[1] Refer to Note 1

[2] Certain amounts have been restated to correct the misstatement discussed in Note 1.

[3] Derived from audited financial statements.