Aggregate notional amount of a terminated hedge. Expressed as an absolute value.

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Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments.

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Fixed interest rate related to the interest rate derivative.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The estimated value of gains (losses), net anticipated to be transferred in the future from accumulated other comprehensive income into earnings.

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The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Period the derivative contract is outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount of the cost of borrowed funds accounted for as interest expense.

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Amount after tax and reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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Amount after tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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Derivatives and Hedging Activities (Details) - USD ($) $ in Thousands					3 Months Ended		12 Months Ended
	Apr. 03, 2019	Jan. 31, 2019	Dec. 06, 2018	Apr. 19, 2018	Mar. 31, 2019	Mar. 31, 2018	Sep. 30, 2019	Dec. 31, 2018
Derivative instruments and hedging activities disclosures
Amount of gain (loss) recorded in accumulated other comprehensive income					$ (4,466)	$ 609
Interest expense					9,498	7,738
Interest Rate Swap \| Designated as Hedging Instrument
Derivative instruments and hedging activities disclosures
Notional Amount					325,000			$ 375,000
Strike Rate			2.91%
Derivative liabilities recognized in unearned revenue, prepaid rent and other liabitilies					8,400			4,100
Derivative asset recognized in other assets					800			1,100
Derivative terminated or settled		$ 50,000
Term		5 years	7 years
Interest Rate Swap \| Designated as Hedging Instrument \| Subsequent Event
Derivative instruments and hedging activities disclosures
Derivative terminated or settled	$ 175,000
Amount of loss recorded in accumulated other comprehensive income	5,700
Interest Rate Swap \| Designated as Hedging Instrument \| Cash Flow Hedging
Derivative instruments and hedging activities disclosures
Amount of gain (loss) recorded in accumulated other comprehensive income					(4,500)	600
Amount reclassified to interest expense					(200)	(100)
Interest expense					9,500	$ 7,700
Interest Rate Swap \| Designated as Hedging Instrument \| Cash Flow Hedging \| Forecast
Derivative instruments and hedging activities disclosures
Amount estimated to be reclassified as an increase to interest expense							$ 300
Interest Rate Swap \| Designated as Hedging Instrument \| Level 2
Derivative instruments and hedging activities disclosures
Fair Value					(7,606)			(2,938)
Interest rate swap expiring 1/31/2019 \| Designated as Hedging Instrument
Derivative instruments and hedging activities disclosures
Notional Amount								50,000
Interest rate swap expiring 1/31/2019 \| Designated as Hedging Instrument \| Level 2
Derivative instruments and hedging activities disclosures
Fair Value								43
Interest rate swap expiring 5/20/2015 \| Designated as Hedging Instrument
Derivative instruments and hedging activities disclosures
Notional Amount					$ 75,000			75,000
Strike Rate					2.83%
Interest rate swap expiring 5/20/2015 \| Designated as Hedging Instrument \| Level 2
Derivative instruments and hedging activities disclosures
Fair Value					$ 773			1,099
Interest rate swap expiring 5/5/2023 \| Designated as Hedging Instrument
Derivative instruments and hedging activities disclosures
Notional Amount					$ 75,000			75,000
Strike Rate					4.12%
Interest rate swap expiring 5/5/2023 \| Designated as Hedging Instrument \| Level 2
Derivative instruments and hedging activities disclosures
Fair Value					$ (1,661)			(897)
Interest rate swap expiring 6/3/2026 \| Designated as Hedging Instrument
Derivative instruments and hedging activities disclosures
Notional Amount					$ 175,000			175,000
Strike Rate					2.91%
Interest rate swap expiring 6/3/2026 \| Designated as Hedging Instrument \| Level 2
Derivative instruments and hedging activities disclosures
Fair Value					$ (6,718)			$ (3,183)
Series A Notes \| Senior Notes \| Subsequent Event
Derivative instruments and hedging activities disclosures
Debt face amount	$ 200,000
Debt Term	7 years
2023 Senior Unsecured Term Loan
Derivative instruments and hedging activities disclosures
Debt Term				5 years