Stockholders' Equity - Additional Information (Detail)	2 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016 USD ($) $ / shares shares	Jun. 30, 2016 USD ($) $ / shares shares	Jun. 30, 2015 USD ($) shares	Jun. 30, 2016 USD ($) Installment $ / shares shares	Jun. 30, 2015 USD ($) shares	Dec. 31, 2015 $ / shares shares	Nov. 30, 2015 USD ($)
Class Of Stock [Line Items]
Capitalized stock-based compensation costs | $		$ 0	$ 0	$ 0	$ 0
Stock options granted | shares		0	0	0	0
Share issued, exercise of options and release of stock awards | shares				1,300,000		1,400,000
Shares settled for tax withholding | shares				564,000	422,000
Stock repurchase program, authorized amount | $							$ 150,000,000
Common stock repurchased, shares | shares		1,200,000		4,100,000
Common stock repurchased, amount | $		$ 14,500,000		$ 52,075,000	$ 0
Remaining value for purchase of common stock under the stock repurchase program | $	$ 98,000,000	$ 98,000,000		$ 98,000,000
Unregistered common stock, shares issued | shares	267,844,000	267,844,000		267,844,000		266,545,000
Common stock, par value | $ / shares	$ 0.01	$ 0.01		$ 0.01		$ 0.01
Stock based compensation expense | $		$ 10,660,000	$ 10,018,000	$ 21,061,000	$ 19,536,000
Netsmart Inc [Member]
Class Of Stock [Line Items]
Stock based compensation expense | $				1,426,000
Liability for outstanding awards | $	$ 1,400,000	$ 1,400,000		$ 1,400,000
Estimated weighted average fair value, Black-Scholes-Merton option pricing model | $ / shares	$ 0.46	$ 0.46		$ 0.46
Estimated share price | $ / shares	$ 1.00	$ 1.00		$ 1.00
Share based compensation expense remaining to be recognized | $	$ 27,500,000	$ 27,500,000		$ 27,500,000
Share based compensation expense remaining to be recognized, 2016 | $	3,600,000	3,600,000		3,600,000
Share based compensation expense remaining to be recognized, 2017 | $	7,200,000	7,200,000		7,200,000
Share based compensation expense remaining to be recognized, 2018 | $	7,200,000	7,200,000		7,200,000
Share based compensation expense remaining to be recognized, 2019 | $	7,200,000	7,200,000		7,200,000
Share based compensation expense remaining to be recognized, 2020 | $	$ 2,300,000	2,300,000		2,300,000
Netsmart Inc [Member] | Class B Non Voting Common Units
Class Of Stock [Line Items]
Options issued during the period | shares	87,989,000
Exercise price | $ / shares	$ 1.00
Intrinsic value related to outstanding Option Units | $	$ 0	$ 0		$ 0
Estimated weighted average fair value, Black-Scholes-Merton option pricing model | $ / shares	$ 0.46	$ 0.46		$ 0.46
Netsmart Inc [Member] | Nathan Holding LLC 2016 Unit Option Plan [Member]
Class Of Stock [Line Items]
Stock options granted | shares	87,989,000
Maximum issuance of options | shares	116,491,000	116,491,000		116,491,000
Options available for further issuance | shares	28,502,000	28,502,000		28,502,000
Exercise price | $ / shares	$ 1.00
Netsmart Inc [Member] | Nathan Holding LLC 2016 Unit Option Plan [Member] | Time Based Option Units [Member]
Class Of Stock [Line Items]
Options issued during the period | shares	62,849,000
Exercise price | $ / shares	$ 1.00
Options vesting period	4 years
Vesting description				The Option Units vest ratably over a period of four years, with the first twenty-five percent vesting at the first anniversary of the issuance and the remaining vesting in equal monthly increments over the following thirty-six months
Netsmart Inc [Member] | Nathan Holding LLC 2016 Unit Option Plan [Member] | Performance Based Option Units [Member]
Class Of Stock [Line Items]
Options issued during the period | shares	25,140,000
Exercise price | $ / shares	$ 1.00
Stock based compensation expense | $				$ 0
Netsmart Inc [Member] | Nathan Holding LLC 2016 Unit Option Plan [Member] | Maximum [Member]
Class Of Stock [Line Items]
Option Units expiration period				10 years
Customary Anti-Dilution Adjustments [Member] | Warrant Issued to Commercial Partner [Member]
Class Of Stock [Line Items]
Number of installments | Installment				4
Number of warrants vesting annually | shares	750,000	750,000		750,000
Warrant expiration period				2026-06
Case 1 [Member] | Customary Anti-Dilution Adjustments [Member] | Warrant Issued to Commercial Partner [Member]
Class Of Stock [Line Items]
Number of warrants issued | shares	900,000	900,000		900,000
Common stock, par value | $ / shares	$ 0.01	$ 0.01		$ 0.01
Sale of common stock, price per share | $ / shares	$ 12.47	$ 12.47		$ 12.47
Case 2 [Member] | Customary Anti-Dilution Adjustments [Member] | Warrant Issued to Commercial Partner [Member]
Class Of Stock [Line Items]
Number of warrants issued | shares	1,000,000	1,000,000		1,000,000
Sale of common stock, price per share | $ / shares	$ 14.34	$ 14.34		$ 14.34
Case 3 [Member] | Customary Anti-Dilution Adjustments [Member] | Warrant Issued to Commercial Partner [Member]
Class Of Stock [Line Items]
Number of warrants issued | shares	1,100,000	1,100,000		1,100,000
Sale of common stock, price per share | $ / shares	$ 15.59	$ 15.59		$ 15.59