Consolidated Statement of Equity (Statement) - USD ($)	Total	Parent [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Shares, Issued			65,704,568			(28,763)
Issuance of stock awards, net of forfeitures			273,173
Treasury Stock Transactions, Excluding Value of Shares Reissued [Abstract]
Purchase of treasury shares						(80,572)
Issuance of treasury shares			(49,446)			49,446
Non-employee directors' deferred compensation plan						(2,883)
Stockholders' Equity Beginning, Including Portion Attributable to Noncontrolling Interest at Dec. 31, 2016		$ 2,622,754,000	$ 657,000	$ 2,489,557,000	$ 134,208,000	$ (1,668,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Purchase of treasury shares	$ (5,325,000)	(5,325,000)				(5,325,000)
Issuance of stock awards, net of forfeitures		0	2,000	(2,000)
Share-based Compensation expense	14,587,000	14,587,000		14,587,000
Issuance of treasury shares		0	0	(3,513,000)		3,513,000
Non-employee directors' deferred compensation plan		(176,000)		0		(176,000)
Net income (Loss) attributable to shareholders	(205,141,000)	(205,141,000)			(205,141,000)
Stockholders' Equity Ending, Including Portion Attributable to Noncontrolling Interest at Sep. 30, 2017		2,426,602,000	$ 659,000	$ 2,500,532,000	$ (70,933,000)	$ (3,656,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity, Other	$ (97,000)	$ (97,000)
Shares, Issued			65,928,295			(62,772)