DEBT

The carrying value of our long-term debt as of December 31, 2016 and 2015 consisted of the following (in millions):



	2016			2015
8.50% Senior notes due 2019	$	480.2		$	566.4
6.875% Senior notes due 2020	735.9			990.9
4.70% Senior notes due 2021	674.4			1,476.7
3.00% Exchangeable senior notes due 2024	604.3			—
4.50% Senior notes due 2024	618.6			619.7
5.20% Senior notes due 2025	662.8			692.5
7.20% Senior notes due 2027	149.2			149.1
7.875% Senior notes due 2040	378.3			379.8
5.75% Senior notes due 2044	970.8			993.5
Total Debt	5,274.5			5,868.6
Less current maturities	(331.9		)	—
Total long-term debt	$	4,942.6		$	5,868.6

Convertible Senior Notes

In December 2016, Ensco Jersey Finance Limited, a wholly-owned subsidiary of Ensco plc, issued $849.5 million aggregate principal amount of unsecured 2024 Convertible Notes in a private offering. The 2024 Convertible Notes are fully and unconditionally guaranteed, on a senior, unsecured basis, by Ensco plc and are exchangeable into cash, our Class A ordinary shares or a combination thereof, at our election. Interest on the 2024 Convertible Notes is payable semiannually on January 31 and July 31 of each year commencing on July 31, 2017. The 2024 Convertible Notes will mature on January 31, 2024, unless exchanged, redeemed or repurchased in accordance with their terms prior to such date. Holders may exchange their 2024 Convertible Notes at their option any time prior to July 31, 2023 only under certain circumstances set forth in the indenture governing the 2024 Convertible Notes. On or after July 31, 2023, holders may exchange their 2024 Convertible Notes at any time, regardless of the foregoing circumstances. The initial exchange rate is 71.3343 shares per $1,000 principal amount of notes, representing an initial exchange price of $14.02 per share, and is subject to adjustment upon certain events. The 2024 Convertible Notes may not be redeemed by us except in the event of certain tax law changes. The total net proceeds from this offering, including issuance costs accrued as of December 31, 2016, were $822.8 million.

Holders may exchange their notes at their option at any time prior to July 31, 2023 only under the following circumstances: (i) during any calendar quarter commencing after the calendar quarter ending on March 31, 2017, if the last reported sale price of our Class A ordinary shares for at least 20 trading days during the period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the applicable exchange price on each of such 20 trading days; (ii) during the five business day period after any five consecutive trading day period (the "measurement period") in which the trading price (as defined in the indenture governing the 2024 Convertible Notes) per $1,000 principal amount of 2024 Convertible Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of our Class A ordinary shares and the applicable exchange rate on each such trading day; (iii) upon the occurrence of specified corporate events; or (iv) if Ensco Jersey Finance Limited calls any or all of the 2024 Convertible Notes for redemption in the event of certain tax law changes, at any time prior to the close of business on the business day immediately preceding the redemption date. As of December 31, 2016, none of the conditions allowing holders of the 2024 Convertible Notes to convert had been met.

If a fundamental change (as defined in the indenture for the 2024 Convertible Notes) occurs, holders of the 2024 Convertible Notes may require us to repurchase for cash all or any portion of their notes at a repurchase price equal to 100% of the principal amount of the notes to be repurchased, plus accrued and unpaid interest, if any, to, but excluding the repurchase date.

Upon conversion of the 2024 Convertible Notes, holders will receive cash, our Class A ordinary shares, or a combination thereof, at our election. Our intent is to settle the principal amount of the 2024 Convertible Notes in cash upon conversion. If the conversion value exceeds the principal amount (i.e., our share price exceeds the exchange price on the date of conversion), we expect to deliver shares equal to our conversion obligation in excess of the principal amount. During each respective reporting period that our average share price exceeds the exchange price, an assumed number of shares required to settle the conversion obligation in excess of the principal amount will be included in the denominator for our computation of diluted EPS using the treasury stock method. See "Note 1 - Description of the Business and Summary of Significant Accounting Policies" for additional information regarding the impact to our EPS.

The 2024 Convertible Notes were separated into their liability and equity components and included in long-term debt and additional paid-in capital on our consolidated balance sheet, respectively. The carrying amount of the liability component was calculated by measuring the estimated fair value of a similar liability that does not include an associated conversion feature. The carrying amount of the equity component representing the conversion feature was determined by deducting the fair value of the liability component from the principal amount of the 2024 Convertible Notes. The difference between the carrying amount of the liability and the principal amount is amortized to interest expense over the term of the 2024 Convertible Notes using the effective interest method and, together with the coupon interest, results in an effective interest rate of approximately 8% per annum. The equity component is not remeasured if we continue to meet certain conditions for equity classification.

The costs related to the issuance of the 2024 Convertible Notes were allocated to the liability and equity components based on their relative fair values. Issuance costs attributable to the liability component are amortized to interest expense over the term of the notes using the effective interest method and the issuance costs attributable to the equity component were recorded to additional paid-in capital on our consolidated balance sheet.

As of December 31, 2016, the 2024 Convertible Notes consist of the following (in millions):



Liability component:
Principal	$	849.5
Less: Unamortized debt discount and issuance costs	(245.2		)
Net carrying amount	$	604.3
Equity component, net	$	220.0

For the year ended December 31, 2016, we recognized $1.3 million associated with coupon interest and $1.5 million associated with the amortization of debt discount and issuance costs.

The indenture governing the 2024 Convertible Notes contains customary events of default, including failure to pay principal or interest on such notes when due, among others. The indenture also contain certain restrictions, including, among others, restrictions on our ability and the ability of our subsidiaries to create or incur secured indebtedness, enter into certain sale/leaseback transactions and enter into certain merger or consolidation transactions.

Senior Notes

During 2015, we issued $700.0 million aggregate principal amount of unsecured 5.20% senior notes due 2025 (the “2025 Notes”) at a discount of $2.6 million and $400.0 million aggregate principal amount of unsecured 5.75% senior notes due 2044 (the “New 2044 Notes”) at a discount of $18.7 million in a public offering. Interest on the 2025 Notes is payable semiannually on March 15 and September 15 of each year. Interest on the New 2044 Notes is payable semiannually on April 1 and October 1 of each year.

During 2014, we issued $625.0 million aggregate principal amount of unsecured 4.50% senior notes due 2024 (the "2024 Notes") at a discount of $850,000 and $625.0 million aggregate principal amount of unsecured 5.75% senior notes due 2044 (the "Existing 2044 Notes" and together with the New 2044 Notes, the "2044 Notes") at a discount of $2.8 million. Interest on the 2024 Notes and the Existing 2044 Notes is payable semiannually on April 1 and October 1 of each year. The Existing 2044 Notes and the New 2044 Notes are treated as a single series of debt securities under the indenture governing the notes.

During 2011, we issued $1.5 billion aggregate principal amount of unsecured 4.70% senior notes due 2021 (the “2021 Notes”) at a discount of $29.6 million in a public offering. Interest on the 2021 Notes is payable semiannually on March 15 and September 15 of each year.

Upon consummation of the Pride acquisition during 2011, we assumed outstanding debt comprised of $900.0 million aggregate principal amount of unsecured 6.875% senior notes due 2020, $500.0 million aggregate principal amount of unsecured 8.5% senior notes due 2019 and $300.0 million aggregate principal amount of unsecured 7.875% senior notes due 2040 (collectively, the "Acquired Notes" and together with the 2021 Notes, 2024 Notes, 2025 Notes and 2044 Notes, the "Senior Notes"). Ensco plc has fully and unconditionally guaranteed the performance of all Pride obligations with respect to the Acquired Notes. See "Note 15 - Guarantee of Registered Securities" for additional information on the guarantee of the Acquired Notes.

We may redeem the 2024 Notes, 2025 Notes and 2044 Notes in whole, at any time or in part from time to time, prior to maturity. If we elect to redeem the 2024 Notes and 2025 Notes before the date that is three months prior to the maturity date or the 2044 Notes before the date that is six months prior to the maturity date, we will pay an amount equal to 100% of the principal amount of the notes redeemed plus accrued and unpaid interest and a "make-whole" premium. If we elect to redeem the 2024 Notes, 2025 Notes or 2044 Notes on or after the aforementioned dates, we will pay an amount equal to 100% of the principal amount of the notes redeemed plus accrued and unpaid interest but we are not required to pay a "make-whole" premium.

We may redeem each series of the 2021 Notes and the Acquired Notes, in whole or in part, at any time, at a price equal to 100% of their principal amount, plus accrued and unpaid interest and a "make-whole" premium.

The indentures governing the Senior Notes contain customary events of default, including failure to pay principal or interest on such notes when due, among others. The indentures governing the Senior Notes also contain certain restrictions, including, among others, restrictions on our ability and the ability of our subsidiaries to create or incur secured indebtedness, enter into certain sale/leaseback transactions and enter into certain merger or consolidation transactions.

Debentures Due 2027

During 1997, Ensco International Incorporated issued $150.0 million of unsecured 7.20% Debentures due November 15, 2027 (the "Debentures") in a public offering. Interest on the Debentures is payable semiannually in May and November. We may redeem the Debentures, in whole or in part, at any time prior to maturity, at a price equal to 100% of their principal amount, plus accrued and unpaid interest and a "make-whole" premium. The Debentures are not subject to any sinking fund requirements. During 2009, Ensco plc entered into a supplemental indenture to unconditionally guarantee the principal and interest payments on the Debentures. See "Note 15 - Guarantee of Registered Securities" for additional information on the guarantee of the Debentures.

The Debentures and the indenture pursuant to which the Debentures were issued also contain customary events of default, including failure to pay principal or interest on the Debentures when due, among others. The indenture also contains certain restrictions, including, among others, restrictions on our ability and the ability of our subsidiaries to create or incur secured indebtedness, enter into certain sale/leaseback transactions and enter into certain merger or consolidation transactions.

Tender Offers and Open Market Repurchases

During 2016, we launched cash tender offers (the "Tender Offers") to repurchase up to $750 million aggregate purchase price of our outstanding debt. We received tenders totaling $860.7 million for an aggregate purchase price of $622.3 million. We used cash on hand to settle the tendered debt.

Additionally during 2016, we repurchased on the open market $269.9 million of our outstanding debt for an aggregate purchase price of $241.6 million.

Our tender offers and open market repurchases during the year ended December 31, 2016 were as follows (in millions, except percentages):



	Aggregate Principal Amount Repurchased		Aggregate Repurchase Price		Discount %
8.50% Senior notes due 2019	$	62.0	$	55.7	10.2	%
6.875% Senior notes due 2020	219.2		181.5		17.2	%
4.70% Senior notes due 2021	817.0		609.0		25.5	%
4.50% Senior notes due 2024	1.7		0.9		47.1	%
5.20% Senior notes due 2025	30.7		16.8		45.3	%
Total	$	1,130.6	$	863.9	23.6	%

During the year ended December 31, 2016, we recognized pre-tax gains from debt extinguishment of $279.0 million included in other, net, in our consolidated statements of operations related to the Tender Offers and open market repurchases, net of discounts, premiums, debt issuance costs and transaction costs.

Debt to Equity Exchange

During 2016, we entered into a privately-negotiated exchange agreement whereby we issued 1,822,432 Class A ordinary shares, representing less than one percent of our outstanding shares, in exchange for $24.5 million principal amount of our 2044 Notes, resulting in a pre-tax gain from debt extinguishment of $8.8 million.

Exchange Offers

In January 2017, we completed exchange offers (the "Exchange Offers") to exchange our outstanding 8.50% senior notes due 2019, 6.875% senior notes due 2020 and 4.70% senior notes due 2021 for 8.00% senior notes due 2024 and cash. The Exchange Offers resulted in the tender of $649.5 million aggregate principal amount of our outstanding notes that were settled and exchanged as follows (in millions):



	Aggregate Principal Amount Repurchased		8% Senior notes due 2024 Consideration		Cash Consideration⁽¹⁾		Total Consideration
8.50% Senior notes due 2019	$	145.8	$	81.6	$	81.7	$	163.3
6.875% Senior notes due 2020	129.8		69.3		69.4		138.7
4.70% Senior notes due 2021	373.9		181.1		181.4		362.5
Total	$	649.5	$	332.0	$	332.5	$	664.5


⁽¹⁾	As of December 31, 2016, the aggregate amount of principal repurchased with cash of $332.5 million, along with associated premiums, was classified as current maturities of long-term debt on our consolidated balance sheet.

During the first quarter, we expect to recognize a pre-tax loss on the Exchange Offers of approximately $6.0 million, net of premiums and transaction costs.

Redemption of 2016 Senior Notes and U.S. Maritime Administration Obligations

During 2011, we issued $1.0 billion of 3.25% senior notes due 2016 (the “2016 Notes”). During 2015, through the combination of a cash tender offer and subsequent redemption, we utilized a portion of the net proceeds from the 2025 Notes and New 2044 Notes to retire the 2016 Notes, and we recorded a pre-tax loss on debt extinguishment of $30.4 million, net of discounts and unamortized debt issuance costs, included in other, net, in our consolidated statement of operations.

During 2015, we used the remaining net proceeds from the 2025 Notes and New 2044 Notes, together with cash on hand, to redeem the remaining $65.3 million outstanding on our 4.33% U.S. Maritime Administration notes due 2016 and 4.65% U.S. Maritime Administration bonds due 2020. We incurred additional losses on debt extinguishment of $3.1 million, which were included in other, net, in our consolidated statement of operations.

Revolving Credit

We have a $2.25 billion senior unsecured revolving credit facility with a syndicate of banks to be used for general corporate purposes with a term expiring on September 30, 2019 (the "Credit Facility"). During 2016, we extended the maturity of $1.13 billion of the $2.25 billion commitment for one year to September 30, 2020.

Advances under the Credit Facility bear interest at Base Rate or LIBOR plus an applicable margin rate, depending on our credit ratings. We are required to pay a quarterly commitment fee on the undrawn portion of the $2.25 billion commitment, which is also based on our credit ratings.

In February 2016, Moody's announced a downgrade of our credit rating to B1, and in December, Standard & Poor's downgraded our credit rating to BB, which are both ratings below investment grade. The first rating action resulted in the highest applicable margin rates and commitment fees under the Credit Facility, and as a result, the second rating action had no effect on our current costs of borrowing. The applicable margin rates are 0.50% per annum for Base Rate advances and 1.50% per annum for LIBOR advances. Also, our quarterly commitment fee is 0.225% per annum on the undrawn portion of the $2.25 billion commitment.

The Credit Facility requires us to maintain a total debt to total capitalization ratio that is less than or equal to 60%. The Credit Facility also contains customary restrictive covenants, including, among others, prohibitions on creating, incurring or assuming certain debt and liens; entering into certain merger arrangements; selling, leasing, transferring or otherwise disposing of all or substantially all of our assets; making a material change in the nature of the business; and entering into certain transactions with affiliates. We have the right, subject to receipt of commitments from new or existing lenders, to increase the commitments under the Credit Facility by an amount not to exceed $500 million and to extend the maturity of the commitments under the Credit Facility by one additional year.

As of December 31, 2016, we were in compliance in all material respects with our covenants under the Credit Facility. We expect to remain in compliance with our Credit Facility covenants during 2017. We had no amounts outstanding under the Credit Facility as of December 31, 2016 and 2015.

Our access to credit and capital markets depends on the credit ratings assigned to our debt. As a result of recent rating actions by these agencies, we no longer maintain an investment-grade status. Our current credit ratings, and any additional actual or anticipated downgrades in our credit ratings, could limit our available options when accessing credit and capital markets, or when restructuring or refinancing our debt. In addition, future financings or refinancings may result in higher borrowing costs and require more restrictive terms and covenants, which may further restrict our operations. With a credit rating below investment grade, we have no access to the commercial paper market.

Maturities

The descriptions of our senior notes above reflect the original principal amounts issued, which have been subsequently reduced through our tenders, repurchases and exchanges such that the maturities of our debt were as follows (in millions):



	Original Principal		2016 Tenders and Repurchases			2016 Debt to Equity Exchange			Principal Outstanding at December 31, 2016⁽¹⁾		2017 Exchange Offers⁽²⁾			Remaining Principal
8.50% Senior notes due 2019	$	500.0	$	(62.0	)	$	—		$	438.0	$	(145.8	)	$	292.2
6.875% Senior notes due 2020	900.0		(219.2		)	—			680.8		(129.8		)	551.0
4.70% Senior notes due 2021	1,500.0		(817.0		)	—			683.0		(373.9		)	309.1
3.00% Senior notes due 2024	849.5		—			—			849.5		—			849.5
4.50% Senior notes due 2024	625.0		(1.7		)	—			623.3		—			623.3
8.00% Senior notes due 2024	—		—			—			—		332.0			332.0
5.20% Senior notes due 2025	700.0		(30.7		)	—			669.3		—			669.3
7.20% Senior notes due 2027	150.0		—			—			150.0		—			150.0
7.875% Senior notes due 2040	300.0		—			—			300.0		—			300.0
5.75% Senior notes due 2044	1,025.0		—			(24.5		)	1,000.5		—			1,000.5
Total	$	6,549.5	$	(1,130.6	)	$	(24.5	)	$	5,394.4	$	(317.5	)	$	5,076.9


⁽¹⁾	The aggregate principal amount outstanding as of December 31, 2016 excludes net unamortized discounts and debt issuance costs of $119.9 million.


⁽²⁾	As of December 31, 2016, the aggregate amount of principal repurchased with cash of $332.5 million, along with associated premiums, was classified as current maturities of long-term debt on our consolidated balance sheet.

Interest Expense

Interest expense totaled $228.8 million, $216.3 million and $161.4 million for the years ended December 31, 2016, 2015 and 2014, respectively, which was net of interest amounts capitalized of $45.7 million, $87.4 million and $78.2 million in connection with newbuild rig construction and other capital projects.