Fair Value Measurement of Financial Instruments (Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Inputs, Level 1 [Member] | Equity Securities [Member] | Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	$ 627
Fair Value, Inputs, Level 1 [Member] | Equity Securities [Member] | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	627
Fair Value, Inputs, Level 2 [Member] | Revolving Loans [Member] | Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability	115,000	$ 92,787
Fair Value, Inputs, Level 2 [Member] | Revolving Loans [Member] | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability	114,827	92,389
Fair Value, Inputs, Level 2 [Member] | Term Loans Member | Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability	519,850	551,913
Fair Value, Inputs, Level 2 [Member] | Term Loans Member | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability	515,742	542,655
Fair Value, Inputs, Level 3 [Member] | Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability	2,553	2,256
Fair Value, Inputs, Level 3 [Member] | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability	2,553	2,256
Interest Rate Cap [Member] | Fair Value, Inputs, Level 2 [Member] | Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		1,239
Interest Rate Cap [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		$ 1,239
Interest Rate Swap [Member] | Fair Value, Inputs, Level 2 [Member] | Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability	2,019
Interest Rate Swap [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability	$ 2,019