Financing Receivables (Details 1) (Uncollectible receivables [Member], USD $) In Thousands, unless otherwise specified				6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2012	Dec. 31, 2011	Dec. 31, 2010	Jun. 30, 2012 Additions [Member]	Dec. 31, 2011 Additions [Member]	Jun. 30, 2012 Deductions [Member]	Dec. 31, 2011 Deductions [Member]
Schedule of activity of allowance for uncollectible accounts on agent receivables
Beginning of year	$ 2,230	$ 2,226	$ 644
Financing receivable, allowance for credit losses, period increase (decrease)				154	1,724	(150)	(142)
End of year	$ 2,230	$ 2,226	$ 644