Derivative Financial Instruments (Details)	12 Months Ended
	Dec. 31, 2016 USD ($) swaps	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Derivatives, Fair Value [Line Items]
Cross-default minimum threshold	$ 25,000,000
Expected increase to interest expense	2,300,000
Derivatives designated as cash flow hedges in prepaid expenses and other assets [Abstract]
Interest rate swaps	7,619,000	$ 0
Derivatives designated as cash flow hedges in accounts payable, accrued expenses and other liabilities [Abstract]
Interest rate swaps	1,870,000	3,073,000
Amount of unrealized gains/(losses) recognized in accumulated other comprehensive income/(loss) on derivatives (effective portion) [Abstract]
Interest rate swaps	5,703,000	(4,040,000)	$ (5,662,000)
Amount of losses reclassified out of accumulated other comprehensive income/(loss) into contractual interest expense (effective portion) [Abstract]
Interest rate swaps	3,057,000	$ 3,696,000	$ 3,777,000
Floating to Fixed Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Amount of borrowings outstanding, subject to swaps	$ 225,000,000
Number of derivative instruments obtained | swaps	6
Derivative maturity date	Jan. 31, 2019
Weighted average interest rate under derivative instruments (in hundredths)	1.678%
Cross-default minimum threshold	$ 25,000,000
Forward Starting Swaps [Member]
Derivatives, Fair Value [Line Items]
Amount of borrowings outstanding, subject to swaps	$ 150,000,000
Underlying treasury rate term (in years)	10 years
Weighted average interest rate under derivative instruments (in hundredths)	1.90%