Accumulated change, net of tax and losses on terminated interest swaps, in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges. Includes an entity's share of an equity investee's Increase or Decrease in deferred hedging gains or losses.

No definition available.

Equity (Details) - USD ($)							1 Months Ended			3 Months Ended			9 Months Ended		12 Months Ended
Equity (Details) - USD ($)	Nov. 01, 2017	Aug. 02, 2017	May 03, 2017	Mar. 01, 2017	Feb. 03, 2017	Jul. 14, 2016	Aug. 31, 2017	May 31, 2017	Mar. 31, 2017	Sep. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015
Common stock
Proceeds from issuance of shares under public offering													$ 76,225,000
Payment to internalize the management team and terminate the existing management agreement using the proceed from public offering													25,000,000
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss), Net of Tax										$ 205,761			205,761		$ 320,917
Unrealized gain related to available-for-sale securities										$ 200,000			$ 200,000		600,000
Net unrealized losses on derivatives designated as cash flow hedges, net of deferred losses on terminated interest swaps															200,000
Deferred losses on terminated interest swaps															$ 100,000
Noncontrolling Interest
Preferred stock, par value (in dollars per share)										$ 0.01			$ 0.01		$ 0.01
Distributions
Cash dividend declared (in dollars per share)										$ 0.18		$ 0.16	$ 0.53	$ 0.46
Performance
Deferred Compensation
Vesting period (in years)													3 years
Restricted stock units eligible to receive annually													$ 3,000,000
Chief executive officer \| Restricted common stock
Deferred Compensation
Number of fully vested shares issued											74,830
Total grant date fair value											$ 600,000
Vesting percentage											25.00%
Chief executive officer \| Restricted common stock \| First Anniversaries
Deferred Compensation
Vesting percentage											25.00%
Chief executive officer \| Restricted common stock \| Second Anniversaries
Deferred Compensation
Vesting percentage											25.00%
Chief executive officer \| Restricted common stock \| Third Anniversaries
Deferred Compensation
Vesting percentage											25.00%
Chief executive officer \| Performance
Deferred Compensation
Granted of restricted stock units that vest at the end of four-year performance period (in shares)							357,569				448,980
Vesting period (in years)													4 years		4 years	4 years
Total grant date fair value							$ 2,700,000				$ 1,000,000
Percentage increased in long-term equity awards due to equity capitalization growth goals													10.00%
Restricted stock units eligible to receive annually													$ 3,000,000
Expiration period (in years)													5 years
Chief executive officer \| Employee compensation and benefits \| Restricted common stock
Deferred Compensation
Share-based compensation expense											100,000
Chief executive officer \| Employee compensation and benefits \| Performance
Deferred Compensation
Share-based compensation expense							$ 100,000
Chief executive officer \| Employee compensation and benefits \| Performance \| Maximum
Deferred Compensation
Share-based compensation expense											$ 100,000
Employees of the company and a related party \| Restricted common stock
Deferred Compensation
Number of fully vested shares issued									299,750
Total grant date fair value									$ 2,400,000
Vesting percentage									33.00%
Employees of the company and a related party \| Restricted common stock \| March, 2018
Deferred Compensation
Vesting percentage									33.00%
Employees of the company and a related party \| Restricted common stock \| March, 2019
Deferred Compensation
Vesting percentage									33.00%
Employees of the company and a related party \| Employee compensation and benefits \| Restricted common stock
Deferred Compensation
Share-based compensation expense									$ 400,000
Employees of the company and a related party \| Selling and administrative expense \| Restricted common stock
Deferred Compensation
Share-based compensation expense									$ 500,000
8.25% Series A preferred stock
Preferred Stock
Return on the preferred shares issued to third parties by its subsidiary REIT (as a percent)													8.25%	8.25%	8.25%
7.75% Series B preferred stock
Preferred Stock
Return on the preferred shares issued to third parties by its subsidiary REIT (as a percent)													7.75%	7.75%	7.75%
8.50% Series C preferred stock
Preferred Stock
Return on the preferred shares issued to third parties by its subsidiary REIT (as a percent)													8.50%	8.50%	8.50%
Common Stock
Common stock
Number of common stock sold under public offering (in shares)								9,500,000					9,500,000
Issued price per share (in dollars per share)								$ 8.05
Proceeds from issuance of shares under public offering								$ 76,200,000
Payment to internalize the management team and terminate the existing management agreement using the proceed from public offering								$ 25,000,000
Number of shares available under an "At-The-Market" equity offering with JMP Securities LLC										7,500,000			7,500,000
Value of common stock available under shelf registration statement										$ 323,500,000			$ 323,500,000
Aggregate amount of securities filed under shelf registration statement										$ 500,000,000			$ 500,000,000
Distributions
Cash dividend declared (in dollars per share)	$ 0.19	$ 0.18	$ 0.18	$ 0.17
Common Stock \| Non-management members of the Board of Directors
Deferred Compensation
Number of fully vested shares issued									74,375
Common Stock \| Non-management members of the Board of Directors \| Selling and administrative expense
Deferred Compensation
Share-based compensation expense									$ 600,000
Preferred Stock \| 8.25% Series A preferred stock
Distributions
Cash dividend declared on redeemable preferred stock (in dollars per share)	$ 0.515625	0.515625	0.515625		$ 0.515625
Preferred Stock
Return on the preferred shares issued to third parties by its subsidiary REIT (as a percent)	8.25%
Preferred Stock \| 7.75% Series B preferred stock
Distributions
Cash dividend declared on redeemable preferred stock (in dollars per share)	$ 0.484375	0.484375	0.484375		0.484375
Preferred Stock
Return on the preferred shares issued to third parties by its subsidiary REIT (as a percent)	7.75%
Preferred Stock \| 8.50% Series C preferred stock
Distributions
Cash dividend declared on redeemable preferred stock (in dollars per share)	$ 0.53125	$ 0.53125	$ 0.53125		$ 0.53125
Preferred Stock
Return on the preferred shares issued to third parties by its subsidiary REIT (as a percent)	8.50%
ACM Acquisition \| ACM / Our "Former Manager"
Noncontrolling Interest
Consideration in stock to be paid with operating partnership units (in shares)						21,230,769
Number of preferred stock shares paired with each operating partnership units						1
Operating Partnership
Noncontrolling Interest
Conversion ratio for operating partnership units to common stock shares													1
Operating Partnership \| Special voting preferred shares
Noncontrolling Interest
Number of preferred stock shares paired with each operating partnership units													1
Preferred stock, par value (in dollars per share)										$ 0.01			$ 0.01
Voting power of outstanding stock (as a percent)													25.60%
Operating Partnership \| ACM Acquisition
Noncontrolling Interest
Consideration in stock to be paid with operating partnership units (in shares)						21,230,769
Value of operating partnership units issues as consideration						$ 154,800,000