Stock-Based Compensation (Details 4) (Stock Appreciation Rights (SARs) [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012 Y	Mar. 31, 2011
Stock Appreciation Rights (SARs) [Member]
Summary of stock appreciation rights activity
Nonvested shares, beginning balance	657
Non vested, weighted average exercise price, beginning balance
Granted, shares	259	215
Granted, weighted average exercise price
Exercised, shares
Exercised, weighted average exercise price
Forfeited or expired, shares
Forfeited or expired, weighted average exercised price
Nonvested shares, ending balance	916
Vested or expected to vest, shares	916
Vested or expected to vest, weighted average exercise price
Non vested, weighted average remaining contractual term	8.1
Vested or expected to vest, weighted average remaining contractual term	8.1
Vested or expected to vest, aggregate intrinsic value	$ 186
Exercisable, shares	470
Non vested, weighted average exercise price, ending balance
Exercisable, weighted average exercise price
Exercisable, weighted average remaining contractual term	6.8
Non vested, aggregate intrinsic value	186
Exercisable, aggregate intrinsic value	$ 33