Stockholders' Equity - Accumulated Other Comprehensive Income (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($) swap_agreement	Dec. 31, 2016 USD ($)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Number of interest rate swaps | swap_agreement		2
Increase to accumulated other comprehensive loss	$ 27	$ 74
Period of impact on net income	10 years
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Other comprehensive income	$ 397	102	$ 168
Forward Starting Swaps [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	(1,299)	(1,401)
Other comprehensive loss before reclassifications	424	176
Amounts reclassified from accumulated other comprehensive income (loss)	(27)	(74)
Other comprehensive income	397	102
Balance, end of period	(902)	(1,299)	$ (1,401)
Interest Rate Swap [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Increase to accumulated other comprehensive loss	(400)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	1,300
Balance, end of period	$ 900	$ 1,300