Segment Information- Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
Net service revenue	$ 292,386	$ 272,872	$ 260,210	$ 246,618	$ 235,443	$ 230,797	$ 226,031	$ 222,552	$ 1,072,086	$ 914,823	$ 816,366
Cost of service revenue									675,810	557,650	480,878
Provision for bad debts									9,484	14,790	19,243
General and administrative expenses									310,539	270,622	247,919
Loss (gain) on disposal of assets									60	1,199	710
Impairment of intangibles and other									1,511	0	1,273
Operating income									74,682	70,562	66,343
Interest expense									(3,876)	(2,936)	(2,302)
Non-operating income									524	492	457
Income from continuing operations before income taxes and noncontrolling interests									71,330	68,118	64,498
Income tax expense									10,944	22,176	22,848
Income from continuing operations									60,386	45,942	41,650
Less net income attributable to noncontrolling interests									10,274	9,359	9,315
Net Income Attributable to LHC Group Inc.'s Common Stockholders	18,435	$ 10,906	$ 11,304	$ 9,467	9,817	$ 9,616	$ 9,464	$ 7,686	50,112	36,583	32,335
Total assets	793,702				614,071				793,702	614,071	566,054
Home-based services [Member]
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
Net service revenue									783,507	665,896	613,188
Cost of service revenue									482,179	398,450	354,750
Provision for bad debts									5,924	9,609	15,736
General and administrative expenses									229,264	203,418	190,591
Loss (gain) on disposal of assets									101	857	544
Impairment of intangibles and other									1,511	0	1,245
Operating income									64,528	53,562	50,322
Interest expense									(2,906)	(2,216)	(1,819)
Non-operating income									360	422	397
Income from continuing operations before income taxes and noncontrolling interests									61,982	51,768	48,900
Income tax expense									9,509	16,505	17,173
Income from continuing operations									52,473	35,263	31,727
Less net income attributable to noncontrolling interests									9,102	6,876	7,424
Net Income Attributable to LHC Group Inc.'s Common Stockholders									43,371	28,387	24,303
Total assets	534,385				427,782				534,385	427,782	394,392
Facility-based services [Member]
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
Net service revenue									82,473	70,088	76,122
Cost of service revenue									54,418	43,238	46,146
Provision for bad debts									900	983	689
General and administrative expenses									25,813	21,212	22,426
Loss (gain) on disposal of assets									(63)	(45)	45
Impairment of intangibles and other									0		0
Operating income									1,405	4,700	6,816
Interest expense									(194)	(259)	(207)
Non-operating income									90	31	19
Income from continuing operations before income taxes and noncontrolling interests									1,301	4,472	6,628
Income tax expense									222	1,535	2,347
Income from continuing operations									1,079	2,937	4,281
Less net income attributable to noncontrolling interests									35	674	958
Net Income Attributable to LHC Group Inc.'s Common Stockholders									1,044	2,263	3,323
Total assets	55,871				36,679				55,871	36,679	38,786
Hospice Entity [Member]
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
Net service revenue									159,197	134,948	85,854
Cost of service revenue									103,969	83,359	50,906
Provision for bad debts									1,910	3,401	1,002
General and administrative expenses									45,516	37,207	26,437
Loss (gain) on disposal of assets									22	338	80
Impairment of intangibles and other									0		0
Operating income									7,780	10,643	7,429
Interest expense									(582)	(317)	(253)
Non-operating income									71	25	38
Income from continuing operations before income taxes and noncontrolling interests									7,269	10,351	7,214
Income tax expense									1,057	3,485	2,541
Income from continuing operations									6,212	6,866	4,673
Less net income attributable to noncontrolling interests									1,248	1,867	1,077
Net Income Attributable to LHC Group Inc.'s Common Stockholders									4,964	4,999	3,596
Total assets	155,230				116,090				155,230	116,090	101,641
Community-Based Services [Member]
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
Net service revenue									46,909	43,891	41,202
Cost of service revenue									35,244	32,603	29,076
Provision for bad debts									750	797	1,816
General and administrative expenses									9,946	8,785	8,465
Loss (gain) on disposal of assets									0	49	41
Impairment of intangibles and other									0	0	28
Operating income									969	1,657	1,776
Interest expense									(194)	(144)	(23)
Non-operating income									3	14	3
Income from continuing operations before income taxes and noncontrolling interests									778	1,527	1,756
Income tax expense									156	651	787
Income from continuing operations									622	876	969
Less net income attributable to noncontrolling interests									(111)	(58)	(144)
Net Income Attributable to LHC Group Inc.'s Common Stockholders									733	934	1,113
Total assets	$ 48,216				$ 33,520				$ 48,216	$ 33,520	$ 31,235