Derivative Financial Instruments Effectiveness Testing (Details) - Interest rate swap agreements [Member] - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Gain/(loss) reclassified from accumulated other comprehensive income/(loss) into earnings due to ineffectiveness	$ 0	$ 0	$ 0	$ 0
Existing net losses realized and recorded as interest expense	$ 600,000	$ 400,000	1,500,000	$ 1,100,000
Existing net losses expected to be realized within the next 12 months			$ 2,000,000