Summary of Property & Equipment (Details) (USD $)	Jun. 30, 2013		Dec. 31, 2012
Property And Equipment [Abstract]
Machinery and equipment	$ 70,704,000		$ 68,713,000
Leashold improvements	96,530,000		88,653,000
Furniture, fixtures, and other	23,872,000		20,827,000
Construction-in-progress	9,465,000		8,766,000
Property and equipment, gross	200,571,000	[1]	186,959,000	[1]
Less: Accumulated depreciation	(111,801,000)	[2]	(104,718,000)	[2]
Property and equipment, net	88,770,000		82,241,000
Gross equipment held under capital leases	200,000		100,000
Depreciation for equipment held under capital leases	$ 100,000		$ 100,000

[1] Includes $0.2 million and $0.1 million of certain equipment held under capital leases and classified as equipment as of June 30, 2013 and December 31, 2012, respectively.

[2] Includes $0.1 million and $0.1 million of accumulated depreciation related to certain equipment held under capital leases as of June 30, 2013 and December 31, 2012, respectively, which are depreciated using the straight-line method over the lease term.