Debt

The following table provides details of the carrying values of debt as of the dates indicated (in millions):



Description	Maturity Date	March 31, 2014			December 31, 2013
Credit facility	October 29, 2018	$	128.6		$	53.0
4.875% senior notes	March 15, 2023	400.0			400.0
2011 4.0% senior convertible notes	June 15, 2014	104.6			103.8
2011 4.25% senior convertible notes	December 15, 2014	95.1			94.5
2009 4.0% senior convertible notes	June 15, 2014	9.6			9.6
2009 4.25% senior convertible notes	December 15, 2014	3.0			3.0
Capital lease obligations, weighted average interest rate of 2.9%	In installments through March 30, 2020	123.2			126.0
Notes payable for equipment, weighted average interest rate of 3.0%	In installments through May 1, 2018	30.1			26.9
Total debt		$	894.2		$	816.8
Less current maturities		(52.9		)	(51.4		)
Long-term debt		$	841.3		$	765.4

Credit Facility

The Company has a senior secured credit facility, referred to as the 2013 Credit Facility. The 2013 Credit Facility matures on October 29, 2018 and has a maximum available borrowing capacity of $750 million, of which up to $100 million may be borrowed in Canadian dollars. As of March 31, 2014 and December 31, 2013, the Company had outstanding revolving loans under the 2013 Credit Facility of $128.6 million and $53.0 million, respectively, which accrued interest at a weighted average rate of approximately 2.08% and 2.14% per annum, respectively. Letters of credit of approximately $134.7 million and $134.8 million were outstanding as of March 31, 2014 and December 31, 2013, respectively. The remaining borrowing capacity of $486.8 million and $562.1 million as of March 31, 2014 and December 31, 2013, respectively, was available for revolving loans, or up to $315.3 million and $315.2 million, respectively, of new letters of credit. Outstanding letters of credit mature at various dates and most have automatic renewal provisions, subject to prior notice of cancellation. As of March 31, 2014 and December 31, 2013, interest on outstanding letters of credit accrued at 0.75% per annum for performance standby letters of credit and at 1.50% per annum for financial standby letters of credit. The unused facility fee was 0.30% as of both March 31, 2014 and December 31, 2013. The 2013 Credit Facility is guaranteed by certain subsidiaries of the Company.

For additional information regarding the Company's 2013 Credit Facility see Note 9 - Debt in the notes to the Company's consolidated financial statements included in its Annual Report on Form 10-K for the year ended December 31, 2013.

Senior Convertible Notes

Unamortized debt discount and financing costs associated with the Company's 2011 Convertible Notes totaled $2.7 million and $4.0 million as of March 31, 2014 and December 31, 2013, respectively. The 4.0% senior convertible notes mature in June 2014 and the 4.25% senior convertible notes mature in December 2014. The Company expects to refinance the $215.0 million principal amount of its senior convertible notes on a long-term basis either through its 2013 Credit Facility or through other sources of available funding and, therefore, has reflected the carrying amounts of these notes within long-term debt in the Company's condensed unaudited consolidated balance sheets.

For additional information regarding the Company's senior convertible notes, see Note 9 - Debt in the notes to the Company's consolidated financial statements included in its Annual Report on Form 10-K for the year ended December 31, 2013.

Debt Guarantees and Covenants

The Company’s 4.875% Senior Notes, 2011 Convertible Notes and 2009 Convertible Notes are fully and unconditionally guaranteed on an unsecured, unsubordinated, joint and several basis by certain of the Company's existing and future 100%-owned direct and indirect domestic subsidiaries that are guarantors of the 2013 Credit Facility or other outstanding indebtedness. See Note 18 - Supplemental Guarantor Condensed Unaudited Consolidating Financial Information.

MasTec was in compliance with all provisions and covenants pertaining to its outstanding debt instruments as of March 31, 2014 and December 31, 2013.

Interest Expense, Net

The following table provides details of interest expense, net, for the periods indicated (in millions):



	For the Three Months Ended March 31,
	2014		2013
Interest expense:
Contractual and other interest expense	$	9.7	$	7.9
Accretion of senior convertible note discount	1.4		1.3
Amortization of deferred financing costs	0.9		0.9
Total interest expense	$	12.0	$	10.1
Interest income	0.0		(0.1		)
Interest expense, net	$	12.0	$	10.0