Borrowings (Tables)

12 Months Ended

Dec. 31, 2015

Debt Disclosure [Abstract]

Components of Long-Term Debt

The Company's borrowings at December 31, 2015 and 2014 are as follows:

	2015			2014
	(Dollars in thousands)
Senior Credit Facility:
Revolving credit facility, at a rate of 2.17% at December 31, 2015 and 1.92% at December 31, 2014, due 2018	$	396,000		$	200,000
3.875% Convertible Senior Subordinated Notes due 2017	399,641			399,898
6.875% Senior Subordinated Notes due 2019	—			250,000
5.25% Senior Notes due 2024	250,000			250,000
Securitization program, at a rate of 1.18% at December 31, 2015 and 0.92% at December 31, 2014	43,300			4,700
	1,088,941			1,104,598
Less: Unamortized debt discount on 3.875% Convertible Senior Subordinated Notes due 2017	(22,999		)	(36,197		)
	1,065,942			1,068,401
Current portion of borrowings	(419,942		)	(368,401		)
Long-term borrowings	$	646,000		$	700,000

Interest Expense Amounts Related to Convertible Notes

The following table provides interest expense amounts related to the Convertible Notes for the periods presented:

(in millions)	Year Ended December 31, 2015		Year Ended December 31, 2014		Year Ended December 31, 2013
Interest cost related to contractual interest coupon	$	15.5	$	15.5	$	15.5
Interest cost related to amortization of the discount	$	13.2	$	12.2	$	11.3

Carrying Value of Convertible Notes

The following table provides the carrying value of the Convertible Notes as of December 31, 2015 and 2014:

(in millions)	December 31, 2015			December 31, 2014
Principal amount of the Convertible Notes	$	399.6		$	399.9
Unamortized discount	(23.0		)	(36.2		)
Net carrying amount	$	376.6		$	363.7

Fair Value of Debt

The following table provides the fair value of the Company’s debt as of December 31, 2015 and 2014, categorized by the level of inputs within the fair value hierarchy used to measure fair value (see Note 10 to the consolidated financial statements for further information):

	Fair value of debt
	December 31, 2015		December 31, 2014
	(Dollars in thousands)
Level 1	$	858,709	$	1,024,806
Level 2	687,072		455,222
Total	$	1,545,781	$	1,480,028

Aggregate Amounts of Long-Term Debt

Debt Maturities

As of December 31, 2015, the aggregate amounts of long-term debt, demand loans and debt under the Company’s securitization program that will mature during each of the next four years and thereafter were as follows:

	(Dollars in thousands)
2016(1)	$	442,941
2017	—
2018	396,000
2019	—
2020 and thereafter	250,000

(1) Convertible Notes are included in amounts that will mature in 2016 because, at December 31, 2015, they were convertible in accordance with their terms, which are described in more detail above in this section under “Convertible Notes.”