Financial instruments (Tables)

12 Months Ended

Dec. 31, 2018

Financial Instruments [Abstract]

Schedule of Outstanding Interest Rate Derivatives

As of December 31, 2018, the Company had the following outstanding interest rate derivatives:

Fixed per annum rate swapped for LIBOR	Notional amount as of December 31, 2018		Maximum notional amount(1)		Effective date	Ending date
5.8700%	$	539,114	$	539,114	August 31, 2017	November 28, 2025	(2)
5.4200%		362,437		362,437	September 6, 2007	May 31, 2024
5.6000%		121,600		121,600	June 23, 2010	December 23, 2021	(3)
3.2675%		69,882		69,882	September 8, 2015	September 8, 2020
3.0900%		68,443		68,443	June 5, 2015	June 5, 2020
1.6000%		42,293		42,293	April 7, 2014	March 20, 2019

⁽¹⁾ Over the term of the interest rate swaps, the notional amounts increase and decrease. These amounts represent the peak notional amounts over the remaining term of the swap.

⁽²⁾ Swap counterparty has an early termination right in August 2019 which may require the Company to settle the swap earlier than the termination date. The fair value liability as of December 31, 2018 for this swap is $68,728,000.

⁽³⁾ Prospectively de-designated as an accounting hedge in 2008.

Schedule of Derivatives

The following provides information about the Company’s derivatives:

	2018		2017
Fair value of financial instruments asset
Interest rate swaps	$	113	$	—
Fair value of financial instruments liability
Interest rate swaps		115,853		168,860
Derivative put instrument		11,319		—

Schedule of Gains and Losses Reclassified from Accumulated Other Comprehensive Loss into Earnings

The following table provides information about gains and losses included in net earnings and reclassified from accumulated other comprehensive loss (“AOCL”) into earnings:

	2018			2017			2016
Earnings (loss) on derivatives recognized    in net earnings:
Change in fair value of financial    instruments	$	14,669		$	(12,631	)	$	(29,118	)
Change in fair value of derivative    put instrument		821			—			—
Loss reclassified from AOCL to net    earnings(1)
Interest expense	$	(333	)	$	(1,927	)	$	(3,407	)
Depreciation and amortization		(784	)		(932	)		(966	)

⁽¹⁾ The effective portion of changes in unrealized loss on interest rate swaps was recorded in accumulated other comprehensive income until September 30, 2008 when these contracts were voluntarily de-designated as accounting hedges. The amounts in accumulated other comprehensive income are recognized in earnings when and where the previously hedged interest is recognized in earnings.