Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2016

Significant Accounting Tables Policies [Abstract]

Schedule Of Earnings Per Share

The following table provides a reconciliation of components of basic and diluted net income per common share:

	December 31,
		2016		2015			2014
Net income		$	56,151	$	(3,207,220	)	$	542,851
Weighted average common shares outstanding during the period			153,378		153,192			153,136
Effect of dilutive instruments			703		—			1,558
Weighted average common shares outstanding during the    period including the effects of dilutive instruments			154,081		153,192			154,694
Net income per common share — basic		$	0.37	$	(20.94	)	$	3.54
Net income per common share — fully diluted		$	0.36	$	(20.94	)	$	3.51
Number of shares not included in dilutive earnings per    share that would have been anti-dilutive because the    exercise price was greater than the average market price    of the common shares			1,437		—			1,377

(1) Due to the net loss for the year ended December 31, 2015, 1.7 million shares for options and restricted stock units were anti-dilutive and excluded from the computation of net loss per share.