Long-Term Debt (Tables)

12 Months Ended

Dec. 31, 2017

Debt Disclosure [Abstract]

Summary of Debt

Issuance	Maturity Date of Notes	Early Redemption Date	Basis Point Premium
2019 Notes	April 1, 2019	Prior to March 1, 2019	20 Basis Points
2024 Notes	April 1, 2024	Prior to January 1, 2024	25 Basis Points
2025 Notes	June 1, 2025	Prior to March 1, 2025	30 Basis Points
2026 Notes	July 15, 2026	Prior to April 15, 2026	50 Basis Points
2044 Notes	April 1, 2044	Prior to October 1, 2043	30 Basis Points
2045 Notes	April 1, 2045	Prior to October 1, 2044	30 Basis Points
2047 Notes	June 1, 2047	Prior to June 1, 2047	40 Basis Points

As of December 31, 2017 and 2016, long-term debt consisted of the following (in millions):

	December 31, 2017								December 31, 2016
	Outstanding Principal		Premium (Discount)			Long-Term Debt			Outstanding Principal		Premium (Discount)			Long-Term Debt
ENLK credit facility, due 2020 (1)	$	—	$	—		$	—		$	120.0	$	—		$	120.0
ENLC credit facility, due 2019 (2)	74.6		—			74.6			27.8		—			27.8
2.70% Senior unsecured notes due 2019	400.0		(0.1		)	399.9			400.0		(0.3		)	399.7
7.125% Senior unsecured notes due 2022	—		—			—			162.5		16.0			178.5
4.40% Senior unsecured notes due 2024	550.0		2.2			552.2			550.0		2.5			552.5
4.15% Senior unsecured notes due 2025	750.0		(1.0		)	749.0			750.0		(1.1		)	748.9
4.85% Senior unsecured notes due 2026	500.0		(0.6		)	499.4			500.0		(0.7		)	499.3
5.60% Senior unsecured notes due 2044	350.0		(0.2		)	349.8			350.0		(0.2		)	349.8
5.05% Senior unsecured notes due 2045	450.0		(6.5		)	443.5			450.0		(6.6		)	443.4
5.45% Senior unsecured notes due 2047	500.0		(0.1		)	499.9			—		—			—
Debt classified as long-term	$	3,574.6	$	(6.3	)	3,568.3			$	3,310.3	$	9.6		3,319.9
Debt issuance cost (3)						(26.2		)						(24.6		)
Long-term debt, net of unamortized issuance cost						$	3,542.1							$	3,295.3

(1) Bears interest based on Prime and/or LIBOR plus an applicable margin. The effective interest rate was 2.3% at December 31, 2016.

(2) Bears interest based on Prime and/or LIBOR plus an applicable margin. The effective interest rate was 3.2%and 3.4% at December 31, 2017 and 2016, respectively.

(3) Net of amortization of $12.9 million and $9.0 million at December 31, 2017 and 2016, respectively.

Schedule of Maturities of Long-term Debt

Maturities for the long-term debt as of December 31, 2017 are as follows (in millions):

2018	$	—
2019	474.6
2020	—
2021	—
2022	—
Thereafter	3,100.0
Subtotal	3,574.6
Less: net discount	(6.3		)
Less: debt issuance cost	(26.2		)
Long-term debt, net of unamortized issuance cost	$	3,542.1