5. Property and Equipment

Property and equipment consisted of the following at December 31:

(dollars in thousands)	Estimated Useful Life in Years		2014			2013
Land		—	$	4,813		$	4,360
Buildings and improvements		3 to 39		16,898			16,082
Construction equipment		2 to 12		269,121			233,051
Office equipment		3 to 8		5,778			5,117
				296,610			258,610
Less: Accumulated depreciation and amortization				(147,956	)		(115,679	)
			$	148,654		$	142,931

Depreciation and amortization expense of property and equipment for the years ended December 31, 2014, 2013 and 2012 was $33.1 million, $28.9 million and $24.8 million, respectively.

- Definition

The entire disclosure for long-lived, physical assets used in the normal conduct of business and not intended for resale. Includes, but is not limited to, accounting policies and methodology, roll forwards, depreciation, depletion and amortization expense, including composite depreciation, accumulated depreciation, depletion and amortization expense, useful lives and method used, income statement disclosures, assets held for sale and public utility disclosures.

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