Fair Value Measurements - Schedule of Fair Values of Financial Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	$ 22,660	$ 29,039
Interest rate swap assets (included in “other assets”)	16,859	9,855
Total assets	39,519	38,894
Interest rate swap liabilities (included in “other liabilities”)	48	317
Total liabilities	48	317
Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	22,660	29,039
Total assets	22,660	29,039
Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Interest rate swap assets (included in “other assets”)	16,859	9,855
Total assets	16,859	9,855
Interest rate swap liabilities (included in “other liabilities”)	48	317
Total liabilities	$ 48	$ 317