Related-party transactions (Details)				3 Months Ended		6 Months Ended
	Apr. 01, 2015 extension	Mar. 31, 2015 property	Oct. 17, 2013 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Sep. 30, 2016	Dec. 31, 2015 USD ($)
Related party transaction [Line Items]
Related party receivables				$ 0		$ 0			$ 2,180,000
Related party payables				$ 5,489,000		$ 5,489,000			0
NewSource
Related party transaction [Line Items]
Investments from Residential to NewSource in non-voting preferred stock			$ 18,000,000
Repurchase of non-voting preferred stock by NewSource			18,000,000
Accrued and unpaid cumulative dividends on repurchased shares			$ 1,500,000
Affiliated entity | AAMC
Related party transaction [Line Items]
Base management fee, percent of qualified average invested capital		1.50%
Incentive management fee, return on invested capital				1.75%
Conversion fee, percent of market value of new rental properties		1.50%
Incentive management fee, percent of incentive fee payable in common stock		25.00%
Period in fiscal years return on invested equity capital evaluated for termination of agreement		2 years
Period of time return rate evaluated to date						15 months
Period of time required return rate evaluated per new agreement						21 months
Deficit of return on invested capital						26.89%
Affiliated entity | AAMC | Forecast
Related party transaction [Line Items]
Cumulative deficit of return on invested capital								28.64%
Affiliated entity | AAMC | Minimum
Related party transaction [Line Items]
Incentive management fee, return on invested capital		7.00%
Affiliated entity | AAMC | Maximum
Related party transaction [Line Items]
Incentive management fee, return on invested capital		8.25%
Affiliated entity | Asset management fee, threshold one | AAMC
Related party transaction [Line Items]
Incentive management fee, percent of average invested capital		25.00%
Incentive management fee, percent of invested capital in excess of threshold		20.00%
Affiliated entity | Asset management fee, threshold two | AAMC
Related party transaction [Line Items]
Incentive management fee, percent of average invested capital		1.75%
Base management fee, number of rental properties floor | property		2,500
Incentive management fee, number of rental properties cap | property		4,499
Incentive management fee, number of rental properties, floor | property		2,500
Incentive management fee, percent of invested capital in excess of threshold		22.50%
Affiliated entity | Asset management fee, threshold three | AAMC
Related party transaction [Line Items]
Incentive management fee, percent of average invested capital		2.00%
Incentive management fee, number of rental properties, floor | property		4,500
Incentive management fee, percent of invested capital in excess of threshold		25.00%
Affiliated entity | Asset Management Agreement | AAMC
Related party transaction [Line Items]
Contract term	15 years
Number of potential renewal extensions | extension	2
Automatic renewal term	5 years
Affiliated entity | Conversion fee | AAMC
Related party transaction [Line Items]
Related party expenses				$ 544,000	$ 399,000	$ 946,000	$ 399,000
Affiliated entity | Base management fee | AAMC
Related party transaction [Line Items]
Related party expenses				4,506,000	4,752,000	8,630,000	4,752,000
Affiliated entity | Expense reimbursements | AAMC
Related party transaction [Line Items]
Related party expenses				357,000	0	357,000	750,000
Affiliated entity | Management incentive fee | AAMC
Related party transaction [Line Items]
Related party expenses				0	0	0	14,900,000
Related party receivables									$ 6,900,000
Related party payables				0		0
Affiliated entity | Interest expense | AAMC
Related party transaction [Line Items]
Related party expenses				0	161,000	0	321,000
Affiliated entity | Professional fee sharing for negotiation of AMA | AAMC
Related party transaction [Line Items]
Related party expenses				$ 0	$ 0	$ 0	$ 2,000,000