Fair Value Measurements (Details 1) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at December 31, 2011	$ (1,314)
Net income	1,758
Other comprehensive income	0
Purchases	0
Issuances	0
Sales	0
Settlements	83
Net transfers into / (out of) Level 3	0
Balance at June 30, 2012	$ 527