FIXED ASSETS (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
FIXED ASSETS
Fixed assets, gross	$ 314,860	$ 250,522
Less: accumulated depreciation	(180,308)	(156,826)
Total fixed assets, net	134,552	93,696
Depreciation and amortization	27,283	23,516	$ 17,961
Write-off of fully depreciated assets	2,000
Computer hardware and software, including internal-use software and website development
FIXED ASSETS
Fixed assets, gross	196,923	175,701
Building
FIXED ASSETS
Fixed assets, gross	67,892	44,811
Furniture and equipment
FIXED ASSETS
Fixed assets, gross	15,931	11,396
Land
FIXED ASSETS
Fixed assets, gross	12,781	10,861
Building machinery and equipment
FIXED ASSETS
Fixed assets, gross	7,915	0
Leasehold improvements
FIXED ASSETS
Fixed assets, gross	7,062	7,753
Land improvements
FIXED ASSETS
Fixed assets, gross	6,356	0
Equipment under capital leases
FIXED ASSETS
Fixed assets, gross	21,500	10,000
Less: accumulated depreciation	(8,700)	(4,600)
Depreciation and amortization	$ 4,100	$ 1,600	$ 707

Property, Plant and Equipment, Write-off of Fully Depreciated Assets

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- Definition

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

+ References

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The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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