Financing Activity (Tables)

6 Months Ended

Jun. 30, 2017

Debt Disclosure [Abstract]

Schedule of credit facility interest expense [Table Text Block]

		Three Months Ended June 30,				Six Months Ended June 30,
(in thousands of dollars)		2017		2016		2017		2016
2013 Revolving Facility
	Interest expense	$	645	$	782	$	1,409	$	1,472
	Deferred financing amortization	199		199		398		397
Term Loans
	Interest expense	3,712		3,045		6,547		6,037
	Deferred financing amortization	190		121		377		241

Applicable Credit Spread Over Libor at Various Leverage Levels

		Applicable Margin
Level	Ratio of Total Liabilities to Gross Asset Value	2013 Revolving Facility		Term Loans
1	Less than 0.450 to 1.00	1.20%		1.35%
2	Equal to or greater than 0.450 to 1.00 but less than 0.500 to 1.00	1.25%	(1)	1.45%	(1)
3	Equal to or greater than 0.500 to 1.00 but less than 0.550 to 1.00	1.30%		1.60%
4	Equal to or greater than 0.550 to 1.00	1.55%		1.90%

Carrying and Fair Values of Mortgage Loans

The aggregate carrying values and estimated fair values of mortgage loans based on interest rates and market conditions at June 30, 2017 and December 31, 2016 were as follows:

	June 30, 2017				December 31, 2016
(in millions of dollars)	Carrying Value		Fair Value		Carrying Value		Fair Value
Mortgage loans(1)	$	1,036.6	$	1,040.0	$	1,222.9	$	1,189.6