Acquisition of Real Estate (Consideration for the New Jersey Facility and the Preliminary Allocation of the Fair Value of Assets Acquired) (Details) (Princeton Facility [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015
Business Acquisition [Line Items]
Buildings	$ 35,574
Land	17,976
Intangible assets	16,114
Other	301
Total purchase price	73,300
Buildings, Weighted average useful life	40 years
Deferred Costs [Member]
Business Acquisition [Line Items]
Intangible assets	$ 3,335
Intangible assets, Weighted average useful life	10 years
Other [Member]
Business Acquisition [Line Items]
Intangible assets, Weighted average useful life	10 years
Acquisition Related Intangibles [Member]
Business Acquisition [Line Items]
Intangible assets, Weighted average useful life	10 years