Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2017

Long-term Debt and Capital Lease Obligations [Abstract]

Schedule of Long-Term Debt

Long-term debt, principally to banks and bondholders, consists of:

(in thousands, except interest rates)	March 31, 2017		December 31, 2016
Private placement with a fixed interest rate of 6.84%, due 2017	$50,000		$50,000
Revolving credit agreement with borrowings outstanding at an end of period interest rate of 2.63% in 2017 and 2.58% in 2016 (including the effect of interest rate hedging transactions, as described below), due in 2021	414,000		418,000
Obligation under capital lease, matures 2022	16,176		16,584
Long-term debt	480,176		484,584
Less: current portion	(51,699	)	(51,666	)
Long-term debt, net of current portion	$428,477		$432,918

Schedule of Future Minimum Annual Capital Lease Obilgations

The following schedule presents future minimum annual lease payments under the capital lease obligation and the present value of the minimum lease payments, as of March 31, 2017.

Years ending December 31,	(in thousands)
2017	$1,819
2018	2,473
2019	2,473
2020	2,520
2021	2,520
Thereafter	7,373
Total minimum lease payments	19,178
Less: Amount representing interest	(3,002	)
Present value of minimum lease payments	$16,176