Stockholders' Equity - Reclassifications out of AOCI (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest Expense	$ 13,069	$ 14,315	$ 25,737	$ 28,587
NET INCOME	$ 37,729	$ 25,224	46,908	$ 57,070
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
NET INCOME			274
Amounts reclassified from accumulated other comprehensive income (loss) related to settled interest rate swaps | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest Expense			84
Amounts reclassified from accumulated other comprehensive income (loss) related to current interest rate swaps | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest Expense			$ 190