Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Revenues	$ 129,936	$ 123,725
Costs and expenses:
Cost of revenues, excluding depreciation and amortization	75,049	70,914
Selling, general and administrative expenses	23,535	25,265
Transaction costs	162	417
Shareholder transaction costs	869	1,009
Severance and related costs	634	1,716
Depreciation expense	14,073	13,048
Amortization expense	3,275	2,443
Interest expense, net	8,700	7,495
Other income, net	(483)	(787)
Total costs and expenses	125,814	121,520
Income before income taxes, earnings from unconsolidated investees, and noncontrolling interest	4,122	2,205
Income tax benefit	(3)	(945)
Earnings from unconsolidated investees	(336)	(252)
Net income	4,461	3,402
Less: Net income attributable to noncontrolling interest	(5,075)	(4,592)
Net loss attributable to Alliance HealthCare Services, Inc.	(614)	(1,190)
Comprehensive loss, net of taxes:
Net income	4,461	3,402
Unrealized gain (loss) on hedging transactions, net of taxes of $0 and $0	13	(38)
Reclassification adjustment for losses realized and included in net loss, net of taxes of $0 and $0	19
Total comprehensive income, net of taxes	4,493	3,364
Comprehensive income attributable to noncontrolling interest	(5,075)	(4,592)
Comprehensive loss attributable to Alliance HealthCare Services, Inc.	$ (582)	$ (1,228)
Loss per common share attributable to Alliance HealthCare Services, Inc.:
Basic	$ (0.06)	$ (0.11)
Diluted	$ (0.06)	$ (0.11)
Weighted average number of shares of common stock and common stock equivalents:
Basic	10,973	10,779
Diluted	10,973	10,779