Unaudited Summarized Quarterly Financial Information - Unaudited Quarterly Results of Operations (Detail) - USD ($) $ / shares in Units, $ 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
Quarterly Financial Information Disclosure [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
Gross margin	104,960	100,016	99,052	92,248	91,354	89,965	88,903	86,951	396,276	357,173	335,488
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
Earnings Per Share - Basic:
Net income attributable to LHC Group, Inc.' common stockholders	$ 1.04	$ 0.61	$ 0.64	$ 0.54	$ 0.56	$ 0.55	$ 0.54	$ 0.44	$ 2.83	$ 2.08	$ 1.86
Earnings Per Share - Diluted:
Net income attributable to LHC Group, Inc.' common stockholders	$ 1.02	$ 0.61	$ 0.63	$ 0.53	$ 0.55	$ 0.54	$ 0.54	$ 0.44	$ 2.79	$ 2.07	$ 1.84
Weighted Average Shares Outstanding:
Basic	17,749,872	17,740,818	17,728,567	17,643,463	17,597,190	17,588,163	17,566,097	17,485,766	17,715,992	17,559,477	17,405,379
Diluted	18,043,297	18,010,522	17,964,387	17,817,880	17,764,066	17,719,473	17,685,147	17,633,549	17,961,018	17,682,820	17,547,531