Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income Statement [Abstract]
Revenues	$ 114,418	$ 120,664	$ 224,800	$ 241,417
Costs and expenses:
Cost of revenues, excluding depreciation and amortization	60,094	63,881	120,733	130,020
Selling, general and administrative expenses	20,247	18,078	39,342	38,913
Transaction costs	0	20	80	263
Severance and related costs	298	772	646	1,301
Impairment charges	4,867	0	4,867	0
Loss on extinguishment of debt	17,069	0	17,069	0
Depreciation expense	16,322	20,693	32,838	42,138
Amortization expense	2,911	3,994	6,705	8,006
Interest expense and other, net	11,053	13,679	23,325	27,367
Other expense and (income), net	(385)	1,208	(1,287)	1,362
Total costs and expenses	132,476	122,325	244,318	249,370
Loss before income taxes, earnings from unconsolidated investees, and noncontrolling interest	(18,058)	(1,661)	(19,518)	(7,953)
Income tax benefit	(7,195)	(2,427)	(7,333)	(5,069)
Earnings from unconsolidated investees	(1,408)	(1,161)	(3,142)	(2,239)
Net income (loss)	(9,455)	1,927	(9,043)	(645)
Less: Net income attributable to noncontrolling interest	(3,509)	(2,728)	(6,339)	(4,978)
Net loss attributable to Alliance HealthCare Services, Inc.	(12,964)	(801)	(15,382)	(5,623)
Comprehensive loss, net of taxes:
Net loss attributable to Alliance HealthCare Services, Inc.	(12,964)	(801)	(15,382)	(5,623)
Unrealized gain (loss) on hedging transactions, net of taxes	(192)	37	(272)	92
Comprehensive loss, net of taxes:	$ (13,156)	$ (764)	$ (15,654)	$ (5,531)
Loss per common share attributable to Alliance HealthCare Services, Inc.:
Basic (dollars per share)	$ (1.22)	$ (0.08)	$ (1.45)	$ (0.53)
Diluted (dollars per share)	$ (1.22)	$ (0.08)	$ (1.45)	$ (0.53)
Weighted-average number of shares of common stock and common stock equivalents:
Basic (shares)	10,629	10,633	10,629	10,648
Diluted (shares)	10,629	10,633	10,629	10,648