Fair Value Measurements - Fair Value of Assets and Liabilities (Details) - Interest Rate Swap [Member] - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Derivative assets	$ 1,440	$ 2,539
Derivative liabilities	3,441	1,135
Fair Value, Inputs, Level 2 [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	1,440	2,539
Derivative liabilities	$ 3,441	$ 1,135