Derivative Instruments and Hedging Activities (Schedule of the Notional Amount and Fair Value of Derivative Instruments) (Details)
$ in Thousands |
3 Months Ended |
12 Months Ended |
|
|
|
Mar. 31, 2019
USD ($)
interest_rate_swap_agreement
|
Dec. 31, 2018
USD ($)
|
Apr. 01, 2019
USD ($)
|
Dec. 31, 2017
USD ($)
|
| Derivatives, Fair Value [Line Items] |
|
|
|
|
| Effective Dates |
Apr. 01, 2019
|
|
|
|
| Fair Value of Asset |
$ 3,420
|
$ 6,204
|
|
$ 3,934
|
| Fair Value of (Liability) |
$ (827)
|
0
|
|
(22)
|
| Number of interest rate swap agreements entered into during period | interest_rate_swap_agreement |
2
|
|
|
|
| Secured credit facility, principal amount outstanding |
$ 365,000
|
355,000
|
|
220,000
|
| Variable Rate, Subject To Interest Rate Swap [Member] |
|
|
|
|
| Derivatives, Fair Value [Line Items] |
|
|
|
|
| Secured credit facility, principal amount outstanding |
100,000
|
100,000
|
|
100,000
|
| Term Loan [Member] | Variable Rate, Subject To Interest Rate Swap [Member] |
|
|
|
|
| Derivatives, Fair Value [Line Items] |
|
|
|
|
| Secured credit facility, principal amount outstanding |
100,000
|
100,000
|
|
100,000
|
| Interest Rate Swaps [Member] | Designated as Hedging Instrument [Member] |
|
|
|
|
| Derivatives, Fair Value [Line Items] |
|
|
|
|
| Outstanding Notional Amount |
$ 497,205
|
$ 347,435
|
|
347,699
|
| Interest Rate Swaps [Member] | Designated as Hedging Instrument [Member] | Minimum [Member] |
|
|
|
|
| Derivatives, Fair Value [Line Items] |
|
|
|
|
| Effective Dates |
Jul. 01, 2016
|
Jul. 01, 2016
|
|
|
| Maturity Dates |
Dec. 22, 2020
|
Dec. 22, 2020
|
|
|
| Interest Rate Swaps [Member] | Designated as Hedging Instrument [Member] | Maximum [Member] |
|
|
|
|
| Derivatives, Fair Value [Line Items] |
|
|
|
|
| Effective Dates |
Apr. 01, 2019
|
Nov. 16, 2017
|
|
|
| Maturity Dates |
Apr. 27, 2023
|
Nov. 16, 2022
|
|
|
| Other Assets, Net [Member] | Interest Rate Swaps [Member] | Designated as Hedging Instrument [Member] |
|
|
|
|
| Derivatives, Fair Value [Line Items] |
|
|
|
|
| Fair Value of Asset |
$ 3,420
|
$ 6,204
|
|
3,934
|
| Accounts Payable and Other Liabilities [Member] | Interest Rate Swaps [Member] | Designated as Hedging Instrument [Member] |
|
|
|
|
| Derivatives, Fair Value [Line Items] |
|
|
|
|
| Fair Value of (Liability) |
$ (827)
|
$ 0
|
|
$ (22)
|
| Subsequent Event [Member] | Term Loan [Member] | Variable Rate, Subject To Interest Rate Swap [Member] |
|
|
|
|
| Derivatives, Fair Value [Line Items] |
|
|
|
|
| Secured credit facility, principal amount outstanding |
|
|
$ 150,000
|
|