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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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- Definition

Amount of cash inflow (outflow) from financing activities, including discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit.

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- Definition

Amount of cash inflow (outflow) from investing activities, including discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets.

+ References

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- Definition

Amount of cash inflow (outflow) from operating activities, including discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities.

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- Definition

Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

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No definition available.

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- Definition

Present value of lessee's discounted obligation for lease payments from operating lease.

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- Definition

Amount of lessee's right to use underlying asset under operating lease.

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- Definition

The cash outflow during the period for redemption of redeemable noncontrolling interests.

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- Definition

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.

+ References

No definition available.

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- Definition

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References

No definition available.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

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Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) segment	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Jan. 01, 2019 USD ($)
Property, Plant and Equipment [Line Items]
Acquisition expense		$ 2,171	$ 836
Vesting period (in years)	5 years
Expiration period of options (in years)	10 years
Number of operating segments \| segment	1
Increase (decrease) in cash from operating activities	$ 217,811	227,870	239,810
Increase (decrease) in cash from investing activities	554,891	(283,074)	11,384
Increase (decrease) in cash from financing activities	$ (707,611)	49,581	(237,301)
Minimum [Member]
Property, Plant and Equipment [Line Items]
Co-venture equity ownership percentage	15.00%
Maximum [Member]
Property, Plant and Equipment [Line Items]
Co-venture equity ownership percentage	25.00%
NNN Office Joint Venture [Member]
Property, Plant and Equipment [Line Items]
Co-venture equity ownership percentage	20.00%
Accounting Standards Update 2016-15 [Member]
Property, Plant and Equipment [Line Items]
Increase (decrease) in cash from operating activities		109	4,537
Increase (decrease) in cash from investing activities		(23,958)	21,571
Increase (decrease) in cash from financing activities		(2,899)	$ (5,603)
Accounting Standards Update 2016-02 [Member] \| Subsequent Event [Member] \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Right-of-use asset				$ 35,000
Lease, liability				35,000
Accounting Standards Update 2016-02 [Member] \| Subsequent Event [Member] \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Right-of-use asset				45,000
Lease, liability				$ 45,000
Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Maximum useful life of PPE (in years)	40 years
Office Building [Member] \| Lake Jackson, Texas [Member]
Property, Plant and Equipment [Line Items]
Redemption of noncontrolling interests	$ 7,951
Variable Interest Entity, Primary Beneficiary [Member]
Property, Plant and Equipment [Line Items]
VIE, ownership percentage	96.00%
Variable Interest Entity, Primary Beneficiary [Member] \| Office Building [Member] \| Affiliated Entity [Member] \| Lake Jackson, Texas [Member]
Property, Plant and Equipment [Line Items]
Redemption of noncontrolling interests		$ 7,951