Debt

Debt consisted of the following:

		March 31, 2017
(in thousands)	Maturity	Gross			Unamortized Debt Issuance Costs			Net Carrying Amount
Amended Revolving Credit Facility	2019 - 2020		325,000		$	-			325,000
Term Loan	2017		250,000			(33	)		249,967
2.75% Senior Notes	2019		499,068			(1,937	)		497,131
2.80% Senior Notes	2020		598,704			(3,131	)		595,573
3.50% Senior Notes	2022		399,085			(2,837	)		396,248
3.90% Senior Notes	2024		497,201			(3,033	)		494,168
3.95% Senior Notes	2025		499,224			(3,752	)		495,472
Total debt			3,068,282			(14,723	)		3,053,559
Current portion of debt			(250,000	)		33			(249,967	)
Debt (less current portion)		$	2,818,282		$	(14,690	)	$	2,803,592
Fair value of debt *								$	3,108,663

		December 31, 2016
(in thousands)	Maturity	Gross			Unamortized Debt Issuance Costs			Net Carrying Amount
Amended Revolving Credit Facility	2019 - 2020		475,000		$	-			475,000
Term Loan	2017		250,000			(68	)		249,932
2.75% Senior Notes	2019		498,979			(2,124	)		496,855
2.80% Senior Notes	2020		598,602			(3,378	)		595,224
3.50% Senior Notes	2022		399,040			(2,975	)		396,065
3.90% Senior Notes	2024		497,110			(3,133	)		493,977
3.95% Senior Notes	2025		499,200			(3,867	)		495,333
Total debt			3,217,931			(15,545	)		3,202,386
Current portion of debt			(250,000	)		68			(249,932	)
Debt (less current portion)		$	2,967,931		$	(15,477	)	$	2,952,454
Fair value of debt *								$	3,254,862
*The fair value of the Senior Notes was estimated using level 2 inputs comprised of quoted prices in active markets, market indices and interest rate measurements for debt with similar remaining maturity.

Revolving Credit Facility

In May 2015, we entered into the Amended Revolving Credit Facility (the “Amended Revolving Credit Facility”). The Amended Revolving Credit Facility permits borrowings up to an aggregate principal amount of $900.0 million, which may be increased to $1,150.0 million at our option. The Amended Revolving Credit Facility matures in March 2020, with the exception of $32.5 million, which matures in March 2019.

Borrowings under the Amended Revolving Credit Facility incur interest charges based on the Company’s credit rating, with drawn amounts incurring interest at LIBOR plus a range of 69 to 130 basis points and a facility fee ranging from 6 to 20 basis points, also subject to the Company’s credit ratings.

The Company had outstanding borrowings under the Amended Credit Facility of $325.0 million and $475.0 million as of March 31, 2017 and December 31, 2016, respectively. Interest was calculated at a rate of approximately 1.91% and 1.54% for the three months ended March 31, 2017 and March 31, 2016, respectively. Outstanding letters of credit under the Amended Revolving Credit Facility totaled $0.8 million and $0.8 million as of March 31, 2017 and December 31, 2016, respectively.

Term Loan

In June 2015, we entered into a $250.0 million senior unsecured Term Loan (the “Term Loan”) agreement. The Term Loan has a maturity date of June 2017, with outstanding borrowings incurring interest at LIBOR plus a range of 62.5 to 137.5 basis points, subject to the Company’s credit ratings. The weighted average interest rate on the Term Loan was 1.88% and 1.52% for the three months ended March 31, 2017 and March 31, 2016, respectively. The Term Loan is classified within current portion of debt on our condensed consolidated balance sheets.

Debt Issuance Costs

Amounts capitalized and included as a reduction against debt on our condensed consolidated balance sheets included $14.7 million and $15.5 million of debt issuance costs as of March 31, 2017 and December 31, 2016, respectively. Debt issuance costs of $1.0 million and $1.1 million related to the Amended Credit Facility are included within other non-current assets on our condensed consolidated balance sheets as of March 31, 2017 and December 31, 2016, respectively. We amortized $1.3 million and $1.7 million of debt issuance and debt discount costs within interest expense in our condensed consolidated statements of operations for the three months ended March 31, 2017 and March 31, 2016, respectively.

Debt Covenants

The Amended Revolving Credit Facility, the Term Loan and all of our Senior Notes include certain affirmative and negative covenants, including limitations on the incurrence of additional indebtedness and maintenance of a maximum leverage ratio.