Debt (Outstanding Debt Including Capital Leases) (Details) - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Weighted average coupon interest rate	3.86%
Total debt and lease obligations	$ 1,403,856	$ 1,356,674
Less net debt issuance costs	(10,662)	(11,557)
Total outstanding debt, net	$ 1,393,194	1,345,117
Revolving Credit Facility
Debt Instrument [Line Items]
Weighted average coupon interest rate	3.40%
Maturity date	Dec. 17, 2022
Outstanding debt	$ 255,645	252,000
Term Loan I
Debt Instrument [Line Items]
Weighted average coupon interest rate	3.48%
Maturity date	Dec. 17, 2023
Outstanding debt	$ 350,000	350,000
Term Loan II
Debt Instrument [Line Items]
Weighted average coupon interest rate	3.51%
Maturity date	Apr. 27, 2024
Outstanding debt	$ 350,000	350,000
Lenexa Mortgage
Debt Instrument [Line Items]
Weighted average coupon interest rate	4.10%
Maturity date	May 01, 2022
Outstanding debt	$ 1,775	1,801
Finance Leases
Debt Instrument [Line Items]
Weighted average coupon interest rate	4.34%
Maturity date description	2019 - 2038
Outstanding debt	$ 46,436	2,873
Operating Partnership Quality Tech LP And QTS Finance Corporation
Debt Instrument [Line Items]
Weighted average coupon interest rate	4.75%
Maturity date	Nov. 15, 2025
Outstanding debt	$ 400,000	$ 400,000

Amount of short-term and long-term debt and lease obligation.

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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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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Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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Description of the maturity date of the debt instrument including whether the debt matures serially and, if so, a brief description of the serial maturities.

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Amount, after accumulated amortization, of debt discount (premium).

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Weighted average interest rate of debt outstanding.

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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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