Share-Based Compensation Arrangements (Details) (USD $)	12 Months Ended
	Dec. 31, 2013 Stock Appreciation Rights (SARs) [Member]	Dec. 31, 2012 Stock Appreciation Rights (SARs) [Member]	Dec. 31, 2010 Stock Appreciation Rights (SARs) [Member]	Dec. 31, 2013 Stock Appreciation Rights (SARs) [Member] Minimum [Member]	Dec. 31, 2012 Stock Appreciation Rights (SARs) [Member] Minimum [Member]	Dec. 31, 2011 Stock Appreciation Rights (SARs) [Member] Minimum [Member]	Dec. 31, 2013 Stock Appreciation Rights (SARs) [Member] Maximum [Member]	Dec. 31, 2012 Stock Appreciation Rights (SARs) [Member] Maximum [Member]	Dec. 31, 2011 Stock Appreciation Rights (SARs) [Member] Maximum [Member]	Dec. 31, 2013 Phantom Share Units (PSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	100,539
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period	(48,460)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	52,079	100,539
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 11.14
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price	$ 0.00
Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price	$ 0.00
Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price	$ 13.21
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 11.81	$ 11.14
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number										487,670
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period										23,642
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period										(197,093)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period										(78,277)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number										235,942
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value										$ 5.67
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value										$ 9.02
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value										$ 6.87
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value										$ 4.73
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value										$ 5.98
Fair value of stock appreciation rights
Risk Free Interest Rate				0.16%	0.27%	0.40%	0.78%	0.52%	0.83%
Dividend yield	0.00%	0.00%	0.00%
Expected life (years)			7 years	1 year 2 months 12 days	2 years 2 months 12 days	3 years 2 months	3 years	4 years	5 years
Volatility	62.21%	63.63%	80.66%