Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2013

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

Schedule of Share-based Compensation, Equity Instruments Other Than Options, Activity

The table below summarizes award activity.

	Year Ended December 31
	2013				2012				2011
	Number of Awards		Weighted average grant-date fair value		Number of Awards		Weighted average grant-date fair value		Number of Awards		Weighted average grant-date fair value
Outstanding at beginning of period	1,463,272		$	5.97	1,458,037		$	5.77	1,514,300		$	3.55
Granted	627,488		5.73		601,647		5.93		555,237		8.72
Converted	(526,848	)	5.72		(472,112	)	5.25		(443,300	)	2.45
Expired	(68,950	)	8.25		—		—		—		—
Forfeited	(17,200	)	7.07		(124,300	)	6.24		(168,200	)	4.22
Outstanding at end of period	1,477,762		$	5.83	1,463,272		$	5.97	1,458,037		$	5.77
Vested	506,644		$	4.47	736,541		$	4.90	390,037		$	4.45

Schedule of Share-based Payment Award, Equity Instruments Other Than Options, Valuation Assumptions

The market condition awards were valued using a Monte Carlo simulation technique based on volatility over three years for the awards granted in 2013, 2012 and 2011 using daily stock prices and using the following variables:

	2013	2012	2011
Risk-free interest rate	0.4%	0.4%	1.3%
Volatility	61.0%	90.1%	1.3%