Equity Award Plans (Tables)

12 Months Ended

Dec. 31, 2013

Equity Award Plans

Summary of activity related to stock options during the year

	Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value ($000)
Outstanding at December 31, 2012		541,369		$	46.58
Granted		267,624		$	28.60
Exercised		(26,390	)	$	10.87
Forfeited or expired		(28,134	)	$	57.47
Outstanding at December 31, 2013		754,469		$	41.04		6.1	$	363.9
Exercisable at December 31, 2013		437,282		$	44.30		3.9	$	244.4

Schedule of weighted average assumptions used to determine the grant-date fair value of options granted

	For the year ended December 31,
	2013			2012			2011(1)
Risk free interest rate		1.13	%		0.85	%		0.88	%
Dividend yield		1.10	%		0.55	%		0.52	%
Expected life (years)		4.98			4.95			2.46
Volatility		73.54	%		75.79	%		57.51	%

(1)

Includes fully vested replacement stock options issued on April 1, 2011 in connection with the acquisition of Western Coal described in Note 3, which significantly reduced the expected life as compared with prior periods.

Summary of activity related to restricted stock units during the year

	Shares			Weighted Average Remaining Contractual Term in Years		Aggregate Intrinsic Value ($000)
Outstanding at December 31, 2012		149,271
Granted		121,364
Vested		(38,908	)
Forfeited or expired		(17,719	)
Outstanding at December 31, 2013		214,008			8.18	$	3,644.7

Summary of activity related to performance-based share units during the year

	Shares		Weighted Average Grant Date Fair Value
Outstanding at December 31, 2012		—
Granted		53,874	$	52.38
Vested		—
Forfeited or expired		—
Outstanding at December 31, 2013		53,874