Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2014

Accounting Policies [Abstract]

Summarized Unaudited Financial Information of Equity Method Investments

Summarized financial data as of December 31, 2014 and 2013, and for the years ended December 31, 2014, 2013, and 2012, for the Company's equity method investments for which separate financial statements are not included, pursuant to SEC Regulation S-X Article 3-09, are as follows:

	December 31,
	2014		2013
Current assets	$	19,540	26,655
Non-current assets	109		27
Total assets	19,649		26,682
Current liabilities	4,520		1,276
Net assets	$	15,129	25,406

	Year Ended December 31,
	2014			2013			2012
Revenues, net	$	940		$	1,032		$	—
Operating expenses	17,289			18,498			578
Loss from operations	(16,349		)	(17,466		)	(578		)
Other	35			137			(1		)
Net loss	$	(16,314	)	$	(17,329	)	$	(579	)

Rollforward of Allowance for Doubtful Accounts

The following table shows the activity in the allowance for doubtful accounts for the year ended December 31, 2014:

	2014
Beginning balance	$	—
Charged to operating expenses	565
Ending balance	$	565

Estimated Useful Lives of Property, Plant and Equipment

The estimated useful lives of these assets are as follows:

	Years
Buildings and building improvements	2–23
Furniture and fixtures	1–7
Equipment	1–10
Land improvements	4–15
Computer hardware and software	1–7

Leasehold improvements are amortized over the shorter of the useful life of the asset or the applicable lease term, generally one to fourteen years.