Financing Receivables: (Details 6)	6 Months Ended	12 Months Ended
	Jun. 30, 2012	Dec. 31, 2011
Financial Industry
Financing Receivables by Portfolio Segment
Financing receivables (as a percent)	39.00%	39.00%
Government Industry
Financing Receivables by Portfolio Segment
Financing receivables (as a percent)	15.00%	15.00%
Manufacturing Industry
Financing Receivables by Portfolio Segment
Financing receivables (as a percent)	14.00%	13.00%
Retail Industry
Financing Receivables by Portfolio Segment
Financing receivables (as a percent)	9.00%	9.00%
Services Industry
Financing Receivables by Portfolio Segment
Financing receivables (as a percent)	8.00%	7.00%
Communications Industry
Financing Receivables by Portfolio Segment
Financing receivables (as a percent)	6.00%	6.00%
Other industries
Financing Receivables by Portfolio Segment
Financing receivables (as a percent)	9.00%	11.00%