CONDENSED CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY (Unaudited) - 3 months ended Mar. 31, 2017 - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Beginning Balance at Dec. 31, 2016	$ 2,248,724	$ 1,915	$ 1,042,696	$ 2,116,341	$ (1,134)	$ (911,094)
Beginning Balance (in shares) at Dec. 31, 2016	191,525,872	191,526,000
Net loss	$ (63,539)			(63,539)
Foreign currency translation adjustment	1,049				1,049
Equity offering	471,570	$ 182	471,388
Equity offering (in shares)		18,170,000
Exercise of stock options	$ 223		223
Exercise of stock options (in shares)	10,000	10,000
Issuance of restricted stock (in shares)		33,000
Forfeitures of restricted stock (in shares)		(9,000)
Stock-based compensation	$ 7,131		7,131
Payment of cash dividends	(3,326)			(3,326)
Purchase of treasury stock	(223)					(223)
Ending Balance at Mar. 31, 2017	$ 2,661,609	$ 2,097	$ 1,521,438	$ 2,049,476	$ (85)	$ (911,317)
Ending Balance (in shares) at Mar. 31, 2017	209,729,770	209,730,000