13. Earnings Per Share of the REIT (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2016		Sep. 30, 2016		Jun. 30, 2016		Mar. 31, 2016		Dec. 31, 2015		Sep. 30, 2015		Jun. 30, 2015		Mar. 31, 2015		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings per share of the REIT [Line Items]
Weighted average common shares – basic																	73,003,164	65,184,013	65,486,108
Effect of dilutive securities																	835,872	0	600,271
Weighted average common shares – diluted																	73,839,036	65,184,013	66,086,379
Net income attributable to common shares	$ 33,734		$ 28,524		$ 37,299		$ 24,408		$ (79,871)		$ 19,062		$ 19,668		$ 15,803		$ 123,965	$ (25,338)	$ 78,662
Net income allocated to unvested restricted shares																	(628)	(599)	(484)
Net income attributable to common shares, adjusted																	$ 123,337	$ (25,937)	$ 78,178
Earnings per common share – basic	$ 0.45		$ 0.38		$ 0.50		$ 0.36		$ (1.23)	[1]	$ 0.29	[1]	$ 0.30	[1]	$ 0.24	[1]	$ 1.69	$ (0.40)	$ 1.19
Adjusted net income available to common shares																	$ 123,337	$ (25,937)	$ 78,178
Earnings per common share – diluted	$ 0.44	[1]	$ 0.37	[1]	$ 0.49	[1]	$ 0.36	[1]	$ (1.23)		$ 0.29		$ 0.30		$ 0.24		$ 1.67	$ (0.40)	$ 1.18
Equity Option [Member]
Earnings per share of the REIT [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount																	0	600,000	0
Performance Shares [Member]
Earnings per share of the REIT [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount																	100,000	100,000	100,000

[1] Amounts do not equal full year results due to rounding.