Stockholders' Deficit (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended					6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 Common Stock [Member]	Jun. 30, 2013 Treasury Stock [Member]	Dec. 31, 2012 Treasury Stock [Member]	Jun. 30, 2013 Additional Paid-In Capital [Member]	Jun. 30, 2013 Accumulated Comprehensive Income (Loss) [Member]	Jun. 30, 2013 Accumulated Deficit [Member]	Jun. 30, 2013 Alliance HealthCare Services, Inc. [Member]	Jun. 30, 2013 Noncontrolling Interest [Member]
Increase (Decrease) in Stockholders' Deficit [Roll Forward]
Beginning balance			$ (116,293)		$ 524	$ (2,877)	$ (2,877)	$ 21,507	$ (716)	$ (183,226)	$ (164,788)	$ 48,495
Beginning balance (shares)					10,615,072	140,028	140,028
Exercise of stock options			29					29			29
Exercise of stock options (shares)			3,665	0	3,665
Issuance of restricted stock (shares)					11,999
Share-based payment			735					735			735
Unrealized gain on hedging transaction, net of tax			272						272		272
Net contributions (distributions)			(6,848)									(6,848)
Net (loss) income	(9,455)	1,927	(9,043)	(645)						(15,382)	(15,382)	6,339
Ending balance	$ (131,148)		$ (131,148)		$ 524	$ (2,877)	$ (2,877)	$ 22,271	$ (444)	$ (198,608)	$ (179,134)	$ 47,986
Ending balance (shares)					10,630,736	140,028	140,028