Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
Revenues before reimbursements		$ 186,129	$ 161,445
Reimbursements		16,733	16,623
Total revenues		202,862	178,068
Cost of services before reimbursable expenses		135,356	116,936
Reimbursable expenses		16,733	16,623
Total cost of services		152,089	133,559
General and administrative expenses		35,167	37,079
Depreciation expense		4,586	4,997
Amortization expense		1,372	1,752
Other operating costs		32	983
Operating income (loss)		9,616	(302)
Interest expense		318	828
Interest income		(689)	(119)
Other expense, net		132	361
Income (loss) from continuing operations before income tax expense		9,855	(1,372)
Income tax expense		3,047	225
Net income (loss) from continuing operations		6,808	(1,597)
(Loss) income from discontinued operations, net of tax		(489)	13,450
Net income		6,319	11,853
Less: Income attributable to non-controlling interest, net of tax		(2,038)
Net income attributable to Navigant Consulting, Inc.		$ 4,281	$ 11,853
Basic net income per share
Net income (loss) from continuing operations attributable to Navigant Consulting, Inc.		$ 0.12	$ (0.04)
(Loss) income from discontinued operations, net of tax		(0.01)	0.30
Net income attributable to Navigant Consulting, Inc.	[1]	$ 0.11	$ 0.26
Shares used in computing basic per share data		40,218	45,120
Diluted net income per share
Net income (loss) from continuing operations attributable to Navigant Consulting, Inc.		$ 0.12	$ (0.04)
(Loss) income from discontinued operations, net of tax		(0.01)	0.30
Net income attributable to Navigant Consulting, Inc.	[1]	$ 0.10	$ 0.26
Shares used in computing diluted per share data		41,408	45,120
Net income		$ 6,319	$ 11,853
Other comprehensive (loss) income, net of tax:
Unrealized net (loss) gain, foreign currency translation		(442)	1,369
Unrealized net gain on interest rate derivatives			250
Reclassification adjustment on interest rate derivatives included in interest expense and income tax expense			7
Other comprehensive (loss) income, net of tax		(442)	1,626
Total comprehensive income, net of tax		5,877	13,479
Income attributable to non-controlling interest, net of tax		(2,038)
Total comprehensive income attributable to Navigant Consulting, Inc., net of tax		$ 3,839	$ 13,479

[1] Earnings per share may not foot due to rounding.