Consolidated Statements of Changes in Stockholders' Equity - USD ($)	Total	Common Stock	Additional Paid-in Capital
Retained Earnings (Accumulated Deficit)	$ 87,177,000
Stockholders' Equity Attributable to Noncontrolling Interest	$ 12,323,000
Common Stock, Shares, Issued	48,833,323
Common Stock, Value, Issued	$ 488,000
Treasury Stock, Shares	0
Treasury Stock, Common, Value	$ 0
Stockholders' Equity Attributable to Parent	359,532,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Additional Paid in Capital	271,867,000
Balance at Dec. 31, 2016	401,485,000
Balance at Dec. 31, 2015	371,855,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Amortization of deferred share-based compensation	274,000
Adjustments to Additional Paid in Capital, Share-based Compensation, Stock Options, Requisite Service Period Recognition	361,000
Contributions from noncontrolling interests	$ 2,928,000
Issuance of common stock under 2014 Equity Plan (in shares)	122,586
Issuance of common stock under 2014 Omnibus Equity Incentive Plan	$ 649,000	$ 2,000	$ 647,000
Distributions	(9,755,000)
Net income	35,173,000
Net Income (Loss) Attributable to Parent	23,756,000
Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest	11,417,000
Retained Earnings (Accumulated Deficit)	110,933,000
Stockholders' Equity Attributable to Noncontrolling Interest	$ 16,913,000
Common Stock, Shares, Issued	48,955,909
Common Stock, Value, Issued	$ 490,000
Treasury Stock, Shares	0
Treasury Stock, Common, Value	$ 0
Stockholders' Equity Attributable to Parent	384,572,000
Additional Paid in Capital	273,149,000
Balance at Dec. 31, 2017	433,038,000
Balance at Dec. 31, 2016	401,485,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Amortization of deferred share-based compensation	356,000
Adjustments to Additional Paid in Capital, Share-based Compensation, Stock Options, Requisite Service Period Recognition	289,000
Adjustments to Additional Paid in Capital, Other	198,000
Contributions from noncontrolling interests	$ 438,000
Stock Issued During Period, Shares, Acquisitions	1,477,000
Common stock issued in connection with the investment in Challenger		(15,000)	(14,607,000)
Issuance of common stock under 2014 Equity Plan (in shares)	229,049
Issuance of common stock under 2014 Omnibus Equity Incentive Plan	$ 1,926,000	2,000	1,924,000
Adjustments Related to Tax Withholding for Share-based Compensation	$ (586,000)	(1,000)	(585,000)
Shares Paid for Tax Withholding for Share Based Compensation	(63,057)
Distributions	$ (10,896,000)
Net income	25,206,000
Net Income (Loss) Attributable to Parent	14,970,000
Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest	10,236,000
Retained Earnings (Accumulated Deficit)	$ 125,903,000
Common stock, shares authorized (in shares)	100,000,000
Stockholders' Equity Attributable to Noncontrolling Interest	$ 16,691,000
Common Stock, Shares, Issued	50,598,901
Common Stock, Value, Issued	$ 506,000
Treasury Stock, Shares	0
Treasury Stock, Common, Value	$ 0
Stockholders' Equity Attributable to Parent	416,347,000
Additional Paid in Capital	289,938,000
Balance at Dec. 31, 2018	485,632,000
Balance at Dec. 31, 2017	433,038,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Amortization of deferred share-based compensation	404,000
Adjustments to Additional Paid in Capital, Share-based Compensation, Stock Options, Requisite Service Period Recognition	288,000
Contributions from noncontrolling interests	$ 5,000
Stock Issued During Period, Shares, Acquisitions	20,000
Common stock issued in connection with the investment in Challenger		0
Treasury Stock, Shares, Acquired	(136,756)
Treasury Stock, Value, Acquired, Cost Method	$ (981,000)
Issuance of common stock under 2014 Equity Plan (in shares)	140,211
Issuance of common stock under 2014 Omnibus Equity Incentive Plan	$ 1,082,000	1,000	1,081,000
Adjustments Related to Tax Withholding for Share-based Compensation	$ (412,000)	$ 0	$ (412,000)
Shares Paid for Tax Withholding for Share Based Compensation	(39,228)
Distributions	$ (10,747,000)
Net income	64,535,000
Net Income (Loss) Attributable to Parent	51,623,000
Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest	11,332,000
Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest	62,955,000
Retained Earnings (Accumulated Deficit)	177,526,000
Stockholders' Equity Attributable to Noncontrolling Interest	$ 17,281,000
Common Stock, Shares, Issued	50,719,884
Common Stock, Value, Issued	$ 507,000
Treasury Stock, Shares	(136,756)
Treasury Stock, Common, Value	$ (981,000)
Stockholders' Equity Attributable to Parent	468,351,000
Additional Paid in Capital	$ 291,299,000