Property and Equipment

12 Months Ended

Dec. 31, 2015

Property, Plant and Equipment [Abstract]

Property and equipment, net consisted of the following:



	As of December 31,
	2015			2014
	(in thousands)
Buildings	$	531,627		$	531,642
Furniture and equipment	218,623			202,846
Software	124,469			113,875
Leasehold improvements	106,768			99,942
Computers	52,295			45,893
Total property and equipment, gross	1,033,782			994,198
Less: accumulated depreciation	(336,067		)	(278,386		)
Total property and equipment, net	$	697,715		$	715,812

Total property and equipment, gross, as of December 31, 2015 and 2014, included $106.8 million and $85.6 million, respectively, for property and equipment recorded under capital leases. Accumulated depreciation, as of December 31, 2015 and 2014, included $30.4 million and $13.1 million, respectively, for property and equipment recorded under capital leases.

As of December 31, 2015, included in property and equipment, net were $15.4 million and $4.1 million in capitalized internally developed software costs and related amortization, respectively. As of December 31, 2014, included in property and equipment, net were $11.2 million and $1.2 million in capitalized internally developed software costs and related amortization, respectively.

The Company recorded depreciation expense of $60.0 million, $62.3 million and $47.3 million in 2015, 2014 and 2013, respectively.

In 2014, in connection with the relocation of the Company’s headquarters in Massachusetts from Cambridge to Boston, the Company wrote off certain leasehold improvements that were fully depreciated and no longer utilized. There was no effect on the Company’s net property and equipment at the time of the write off because the Company had previously adjusted the useful lives of these assets to coincide with its relocation when it concluded that the relocation was probable.