Concentration of Credit Risk and Off-Balance Sheet Risk (Tables)

6 Months Ended

Jun. 30, 2014

Revenue and Trade Accounts Receivable from Bidders

The following represents revenue and trade accounts receivable from bidders exceeding 10% of the total in each category:

	Revenue for the three months ended June 30,				Revenue for the six months ended June 30,				Trade Accounts Receivable as of June 30,
Bidder	2014		2013		2014		2013		2014		2013
A		12%		18%		15%		17%		21%		17%
B		13%		12%		11%		11%		13%		13%
C		7%		9%		7%		9%		11%		10%