Long and short-term capital leases (Tables)

12 Months Ended

Dec. 31, 2013

Long and short-term capital leases

Schedule of long and short-term capital leases

	December 31,
	2013			2012
Capital leases to various lessors secured by financed equipment with interest rates ranging from 4.67% to 14.51%. Principal and interest are payable monthly through May 2018	$	949,596		$	701,598
Total long and short-term portions of capital leases		949,596			701,598
Less: short-term portion capital leases		(466,010	)		(337,588	)
Long-term portion of capital leases	$	483,586		$	364,010

Schedule of interest expense related to capital leases

	Year ended December 31,
	2013		2012		2011
Capital leases		60,106		55,699		64,462