Accounts Receivable and Reserves for Credit Losses

In general, the terms of the Company’s trade receivables provide for payment terms of 30 days or less. The Company does not extend revolving credit to its customers with respect to these receivables. The portfolio of receivables is considered to be a large group of smaller balance homogeneous amounts that are collectively evaluated for impairment.

At December 31, 2014, approximately 94 percent of the outstanding balance of total trade accounts receivable was current and approximately 98 percent of the outstanding balance of total trade accounts receivable was less than 60 days past due. At December 31, 2013, approximately 95 percent of the outstanding balance of total trade accounts receivable was current and approximately 99 percent of the outstanding balance was less than 60 days past due. The outstanding balance is made up of receivables from a wide range of industries. No single customer accounted for 10 percent or more of the outstanding receivables at December 31, 2014.

The following table presents changes in reserves for credit losses related to accounts receivable:



	Year ended December 31,
	2014			2013			2012
Balance, beginning of period	$	10,396		$	11,709		$	11,526
Provision for credit losses	32,144			20,200			22,539
Charge-offs	(35,302		)	(27,781		)	(27,961		)
Recoveries of amounts previously charged-off	6,832			6,663			5,605
Currency translation	(151		)	(395		)	—
Balance, end of period	$	13,919		$	10,396		$	11,709