Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Common Shares	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated (Losses) Earnings	Noncontrolling Interests	Total
Balance at Jun. 30, 2017	$ 652	$ 2,185,796	$ 879	$ 88,050	$ 44,887	$ 2,320,264
Balance (in shares) at Jun. 30, 2017	65,179,527
Increase (Decrease) in Stockholders' Equity
Stock-based compensation and related share issuances	$ 1	2,455				2,456
Stock-based compensation and related share issuances (in shares)	129,491
Contributions from non-controlling interests					339	339
Net income (loss)				(139,786)	(3,573)	(143,359)
Other comprehensive loss			(858)			(858)
Dividends declared				(48,437)		(48,437)
Balance at Mar. 31, 2018	$ 653	2,188,251	21	(100,173)	41,653	2,130,405
Balance (in shares) at Mar. 31, 2018	65,309,018
Balance at Dec. 31, 2017	$ 653	2,186,648	687	69,842	41,987	2,299,817
Balance (in shares) at Dec. 31, 2017	65,307,285
Increase (Decrease) in Stockholders' Equity
Stock-based compensation and related share issuances		1,603				1,603
Stock-based compensation and related share issuances (in shares)	1,733
Contributions from non-controlling interests					134	134
Net income (loss)				(153,650)	(468)	(154,118)
Other comprehensive loss			(666)			(666)
Dividends declared				(16,365)		(16,365)
Balance at Mar. 31, 2018	$ 653	2,188,251	21	(100,173)	41,653	2,130,405
Balance (in shares) at Mar. 31, 2018	65,309,018
Balance at Jun. 30, 2018	$ 654	2,192,612	(1,201)	(89,898)	39,102	2,141,269
Balance (in shares) at Jun. 30, 2018	65,360,041
Increase (Decrease) in Stockholders' Equity
Stock-based compensation and related share issuances		3,527				3,527
Stock-based compensation and related share issuances (in shares)	40,263
Other				266		266
Contributions from non-controlling interests		3,210			(428)	2,782
Net income (loss)				67,368	(3,753)	63,615
Other comprehensive loss			$ 1,201	(1,201)
Dividends declared				(51,098)		(51,098)
Balance at Mar. 31, 2019	$ 654	2,199,349		(74,563)	34,921	2,160,361
Balance (in shares) at Mar. 31, 2019	65,400,304
Balance at Dec. 31, 2018	$ 654	2,197,254		(86,238)	35,300	2,146,970
Balance (in shares) at Dec. 31, 2018	65,396,339
Increase (Decrease) in Stockholders' Equity
Stock-based compensation and related share issuances		1,675				1,675
Stock-based compensation and related share issuances (in shares)	3,965
Other				266		266
Contributions from non-controlling interests		420			(201)	219
Net income (loss)				28,772	(178)	28,594
Dividends declared				(17,363)		(17,363)
Balance at Mar. 31, 2019	$ 654	$ 2,199,349		$ (74,563)	$ 34,921	$ 2,160,361
Balance (in shares) at Mar. 31, 2019	65,400,304