CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - 3 months ended Mar. 31, 2017 - USD ($) shares in Thousands, $ in Thousands	Common Shares	Additional Paid-in Capital	Accumulated Deficit	Treasury Stock	Total
Balance at Dec. 31, 2016	$ 3,959	$ 1,975,247	$ (850,410)	$ (47,597)	$ 1,081,199
Balance (in shares) at Dec. 31, 2016	395,859
Increase (Decrease) in Shareholders' Equity
Equity-based compensation		10,069			10,069
Restricted stock awards and units	$ 9	(9)
Restricted stock awards and units (in shares)	957
Purchase of treasury stock		(597)		(518)	(1,115)
Net loss			(28,841)		(28,841)
Balance at Mar. 31, 2017	$ 3,968	$ 1,984,710	$ (879,251)	$ (48,115)	$ 1,061,312
Balance (in shares) at Mar. 31, 2017	396,816