Interest expense (Tables)

6 Months Ended

12 Months Ended

Jun. 30, 2018

Dec. 31, 2017

Interest and Debt Expense [Abstract]

Schedule Of Interest Expense

The following tables present the components of interest expense:

	For the six months ended June 30,
	2018		2017
(Dollars in thousands)
Interest incurred on debt	$	35,473	$	12,086
Related party Promissory Note interest expense		5,090		—
Senior Note redemption premium		4,782		—
Accretion of fair value adjustment on Senior Notes		19,414		3,208
Accretion of original issue discount on 2018 Term Loans		357		—
Amortization of debt issuance costs		1,416		154
Total interest expense	$	66,532	$	15,448

	Successor						Predecessor
	For the year ended December 31, 2017		For the year ended December 31, 2016		For the period August 15 through December 31, 2015		For the period January 1 through August 14, 2015
	(Dollars in thousands)
Interest incurred on debt	$	24,060	$	20,408	$	7,694	$	12,066
Amortization of discount on Senior Subordinated Notes	—		—		—		12,027
Accretion of fair value adjustment on Senior Notes	6,454		6,305		2,305		—
Amortization of debt issuance costs	309		201		—		2,118
Total interest expense	$	30,823	$	26,914	$	9,999	$	26,211