Employee Benefit Plans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012 Plans	Mar. 31, 2011
Compensation and Retirement Disclosure [Abstract]
Number of frozen defined benefit plans	1
Components of net periodic pension expense:
Interest cost	$ 552	$ 603
Expected return on plan assets	(662)	(644)
Amortization of net loss	243	91
Total pension expense	$ 133	$ 50