Stock Options (Tables)

12 Months Ended

Dec. 31, 2013

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Assumptions Used for Estimating Fair Value of Share Based Payments

The following table presents the weighted-average assumptions used to estimate the fair value of the share based payment awards granted in the periods presented:

	Years Ended December 31,
	2013			2012			2011
Risk-free interest rate	1.44		%	0.59		%	1.47		%
Expected volatility	53.89		%	57.05		%	42.28		%
Expected life in months	66			66			66
Weighted-average fair value of grants	$	10.95		$	4.95		$	8.84

Summary of Option Activity

Option activity during the three years ended December 31, 2013 was as follows:

	Years Ended December 31,
	2013				2012				2011
	Number of Shares		Weighted- Average Exercise Price		Number of Shares		Weighted- Average Exercise Price		Number of Shares		Weighted- Average Exercise Price
Outstanding at January 1,	1,026,588		$	18.69	978,688		$	20.89	929,850		$	20.65
Options granted	190,500		22.42		222,100		9.81		224,000		21.61
Options exercised	(437,937	)	20.05		—		—		(79,937	)	19.42
Options forfeited	(77,150	)	22.35		(174,200	)	19.70		(95,225	)	21.55
Outstanding at December 31,	702,001		$	18.46	1,026,588		$	18.69	978,688		$	20.89
Exerciseable at December 31,	245,750		$	19.74	568,985		$	21.46	530,262		$	21.52
Available for grant at December 31,	111,343				78,350				230,950

Changes in Nonvested Stock Options

Changes in nonvested stock options for the year ended December 31, 2013 were as follows:

	Number of Shares		Weighted- Average Grant Date Fair Value Per Share
Nonvested at January 1, 2013	457,603		$	6.49
Granted	190,500		10.95
Vested	(161,527	)	6.69
Forfeited	(30,325	)	7.11
Nonvested at December 31, 2013	456,251		$	8.24