Stockholders' Deficit (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Class Of Stock [Line Items]
Beginning balance	$ (9,503)	$ (77,620)
Exercise of stock options		486
Shareholder transaction		28,629
Share-based payment	381	1,402
Share-based payment income tax benefit		345
Other comprehensive income (loss)	32	(38)
Distributions to noncontrolling interest in subsidiaries	(5,600)	(2,433)
Contributions from noncontrolling interest in subsidiaries	286
Net (loss) income	4,461	3,402
Ending balance	(9,943)	(45,827)
Treasury Stock
Class Of Stock [Line Items]
Beginning balance	$ (3,138)	$ (3,138)
Beginning balance, shares	(157,973)	(157,973)
Ending balance	$ (3,138)	$ (3,138)
Ending balance, shares	(157,973)	(157,973)
Additional Paid-In Capital
Class Of Stock [Line Items]
Beginning balance	$ 61,353	$ 29,297
Exercise of stock options		485
Shareholder transaction		28,629
Share-based payment	381	1,402
Share-based payment income tax benefit		345
Ending balance	61,734	60,158
Accumulated Comprehensive Income
Class Of Stock [Line Items]
Beginning balance	10	(511)
Other comprehensive income (loss)	32	(38)
Ending balance	42	(549)
Accumulated Deficit
Class Of Stock [Line Items]
Beginning balance	(197,900)	(198,393)
Net (loss) income	(614)	(1,190)
Ending balance	(198,514)	(199,583)
Alliance HealthCare Services, Inc.
Class Of Stock [Line Items]
Beginning balance	(139,565)	(172,637)
Exercise of stock options		486
Shareholder transaction		28,629
Share-based payment	381	1,402
Share-based payment income tax benefit		345
Other comprehensive income (loss)	32	(38)
Net (loss) income	(614)	(1,190)
Ending balance	(139,766)	(143,003)
Noncontrolling Interest
Class Of Stock [Line Items]
Beginning balance	130,062	95,017
Distributions to noncontrolling interest in subsidiaries	(5,600)	(2,433)
Contributions from noncontrolling interest in subsidiaries	286
Net (loss) income	5,075	4,592
Ending balance	129,823	97,176
Common Stock
Class Of Stock [Line Items]
Beginning balance	$ 110	$ 108
Beginning balance, shares	10,970,937	10,774,857
Vesting of stock awards, net	18,336
Exercise of stock options		$ 1
Exercise of stock options, shares		100,000
Ending balance	$ 110	$ 109
Ending balance, shares	10,989,273	10,874,857