Derivative Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2018

Derivatives [Line Items]

Schedule of Notional Amounts of Outstanding Derivative Positions

The following table summarizes the terms of the Company's outstanding interest rate swap agreements entered into to manage the Company's exposure to changes in interest rates on its variable rate debt (amounts in thousands):

		Notional Amount
Effective Date	Expiration Date	Date	Amount		Pay Fixed Rate	Receive Variable Rate
12/1/2016	12/1/2021	12/1/2021	A$	372,600	2.44%	AUD-BBR
12/1/2016	12/1/2021	12/1/2021	A$	110,745	2.44%	AUD-BBR
12/1/2016	12/1/2021	12/1/2021	A$	34,155	2.44%	AUD-BBR
8/31/2018	8/31/2021	8/31/2021	$	100,000	2.70%	1-month LIBOR
8/31/2018	8/31/2021	8/31/2021	$	100,000	2.71%	1-month LIBOR
8/31/2018	8/31/2048	8/31/2048	$	100,000	2.84%	1-month LIBOR
8/31/2018	8/31/2048	8/31/2048	$	100,000	2.87%	1-month LIBOR
8/31/2018	8/31/2048	8/31/2048	$	100,000	2.84%	1-month LIBOR

Schedule of Notional Amounts of Expired Derivative

The following table summarizes the Company's interest rate swap agreements that were settled during the year ended December 31, 2018 (dollars in thousands):

		Notional Amount				Receive Variable Rate
Effective Date	Settlement Date	Date	Amount		Paid Fixed Rate
9/30/2016	8/15/2018	9/30/2026	$	100,000	2.76%	1-month LIBOR
9/30/2016	8/15/2018	9/30/2026	$	100,000	2.74%	1-month LIBOR
9/30/2016	8/15/2018	9/30/2026	$	100,000	2.73%	1-month LIBOR

Schedule of Derivative Instruments in Statement of Financial Position, Fair Value

The following table summarizes the estimated fair value of the Company's derivative instruments, based on Level 2 inputs, recorded in the consolidated balance sheets as of December 31, 2018 and 2017 (dollars in thousands):

		Fair Value
	Balance Sheet Location	2018		2017
Asset Derivatives:
Derivatives designated as hedges:
British pound forward contracts	Other assets	$	26,011	$	13,657
Total derivatives designated as hedges		$	26,011	$	13,657
Derivatives not designated as hedges:
Cross-currency swap contract	Prepaid expenses and other	$	19,684	$	5,775
Cross-currency swap contract	Other assets	—		2,887
Total derivatives not designated as hedges		$	19,684	$	8,662
Liability Derivatives:
Derivatives designated as hedges:
Interest rate swap agreements	Accrued expenses	$	1,954	$	1,972
Interest rate swap agreements	Other long-term liabilities	12,441		12,410
British pound forward contracts	Other long-term liabilities	59		829
Total derivatives designated as hedges		$	14,454	$	15,211

Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss)

The following table shows the effect of the Company's derivative instruments designated as cash flow hedges for the years ended December 31, 2018, 2017 and 2016 in other comprehensive income/(loss) (OCI) (dollars in thousands):

	Total Cash Flow Hedge OCI Activity, Net of Tax
	2018			2017		2016
Derivatives Designated as Cash Flow Hedges:
Effective portion of changes in fair value recognized in OCI:
Interest rate swap agreements	$	(130	)	$	372	$	(1,676	)
Foreign currency forward contracts	14			—		—
British pound forward contracts, net(a)	836			1,498		(3,990		)
	$	720		$	1,870	$	(5,666	)

(a) The year ended December 31, 2018 represented a net gain of $9.5 million for the mark-to-market of the British pound forward contracts, partially offset by a net loss of $8.7 million for the mark-to-market of the U.K. intercompany loan. The year ended December 31, 2017 represented a net gain of $9.8 million for the mark-to-market of the U.K. intercompany loan, partially offset by a net loss of $8.3 million for the mark-to-market of the British pound forward contracts. The year ended December 31, 2016 represented a net loss of $18.7 million for the mark-to-market of the U.K. intercompany loan, partially offset by a net gain of $14.7 million for the mark-to-market of the British pound forward contracts.

Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location

The following table shows the effect of the Company's derivative instruments not designated as hedges for the years ended December 31, 2018, 2017 and 2016 in the consolidated statements of operations (dollars in thousands):

	Location of Amount Recognized in Earnings	Amount Recognized in Earnings
		2018			2017			2016
Derivative Instruments Not Designated as Hedges:
Cross-currency swap agreements	Interest (expense)/income	$	—		$	(3,505	)	$	—
Cross-currency swap agreements, net(a)	Other (loss)/income, net	(5,679		)	(2,451		)	(3,267		)
		$	(5,679	)	$	(5,956	)	$	(3,267	)

(a) The year ended December 31, 2018 represented a net loss of $10.4 million for the mark-to-market of the GRail Intercompany Loan, partially offset by a net gain of $4.8 million for the mark-to-market of the Swaps. The year ended December 31, 2017 represented a net loss of $10.8 million for the mark-to-market of the GRail Intercompany Loan, partially offset by a net gain of $8.4 million for the mark-to-market of the Swaps. The year ended December 31, 2016 represented a net loss of $3.9 million for the mark-to-market of the GRail Intercompany Loan, partially offset by a net gain of $0.7 million for the mark-to-market of the Swaps.

Foreign Currency Forward [Member]

Derivatives [Line Items]

Schedule of Derivative Instruments [Table Text Block]

The following table summarizes the Company's foreign currency forward contracts that were settled during the year ended December 31, 2018 (dollars in thousands):

Effective Date	Settlement Date	Notional Amount	Exchange Rate (AUD to USD)
4/18/2018	7/5/2018	$5,379	0.78
5/2/2018	11/5/2018	$4,315	0.75
5/2/2018	12/21/2018	$5,753	0.75

Foreign Exchange Forward [Member]

Derivatives [Line Items]

Schedule of Notional Amounts of Outstanding Derivative Positions

The following table summarizes the Company's outstanding British pound forward contracts (British pounds in thousands):

Effective Date	Settlement Date	Notional Amount	Exchange Rate (GBP to USD)
3/25/2015	3/31/2020	£60,000	1.51
3/25/2015	3/31/2020	£60,000	1.50
6/30/2015	3/31/2020	£2,035	1.57
9/30/2015	3/31/2020	£1,846	1.51
12/31/2015	3/31/2020	£1,873	1.48
3/31/2016	3/31/2020	£1,881	1.45
6/30/2016	3/31/2020	£1,909	1.35
9/30/2016	3/31/2020	£1,959	1.33
12/30/2016	3/31/2020	£1,989	1.28
3/31/2017	3/31/2020	£1,975	1.30
6/30/2017	3/31/2020	£2,026	1.34
10/2/2017	3/31/2020	£2,079	1.36
12/29/2017	3/31/2020	£2,111	1.39
3/29/2018	3/31/2020	£2,096	1.44
6/29/2018	3/31/2020	£2,151	1.36
9/28/2018	3/31/2020	£2,207	1.34
12/31/2018	3/31/2020	£2,240	1.30