Unaudited Quarterly Financial Data (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
Condensed Income Statements, Captions [Line Items]
Proceeds from lease termination			$ 7,685
Total gross revenues	$ 95,326	$ 105,981	116,912	$ 111,277	$ 106,626	$ 105,438	$ 110,333	$ 108,442	$ 429,496	$ 430,839	$ 423,818
Net income (loss)	16,929	(27,612)	56,680	50,453	35,513	(5,200)	50,207	34,371	96,450	114,891	97,463
Net income (loss) attributable to common shareholders	$ 14,391	$ (26,975)	$ 53,875	$ 47,781	$ 33,229	$ (7,629)	$ 47,654	$ 31,829	$ 95,624	$ 111,703	$ 93,104
Net income attributable to common shareholders - basic (in dollars per share)	$ 0.06	$ (0.12)	$ 0.23	$ 0.21	$ 0.14	$ (0.03)	$ 0.20	$ 0.14	$ 0.38	$ 0.45	$ 0.38
Net income (loss) attributable to common shareholders - diluted (in dollars per share)	$ 0.06	$ (0.12)	$ 0.23	$ 0.20	$ 0.14	$ (0.03)	$ 0.20	$ 0.14	$ 0.37	$ 0.45	$ 0.38
LCIF [Member]
Condensed Income Statements, Captions [Line Items]
Proceeds from lease termination			$ 7,685
Total gross revenues	$ 18,739	$ 30,558	40,772	$ 34,100	$ 32,979	$ 30,762	$ 32,301	$ 31,959	$ 124,169	$ 128,001	$ 118,133
Net income (loss)	$ 16,877	$ (61,579)	$ 22,754	$ 18,027	$ 9,969	$ 9,827	$ 11,163	$ 11,356	$ (3,921)	$ 42,315	$ 59,549
Net income (loss) (usd per unit)	$ 0.20	$ (0.74)	$ 0.27	$ 0.22	$ 0.13	$ 0.13	$ 0.16	$ 0.16	$ (0.05)	$ 0.58	$ 0.87
Scenario, Previously Reported [Member]
Condensed Income Statements, Captions [Line Items]
Total gross revenues		$ 106,331	$ 109,577	$ 111,616
Net income (loss)		(27,262)	49,345	50,792
Net income (loss) attributable to common shareholders		$ (26,653)	$ 46,830	$ 48,107
Net income attributable to common shareholders - basic (in dollars per share)		$ (0.11)	$ 0.20	$ 0.21
Net income (loss) attributable to common shareholders - diluted (in dollars per share)		$ (0.11)	$ 0.20	$ 0.21
Scenario, Previously Reported [Member] | LCIF [Member]
Condensed Income Statements, Captions [Line Items]
Total gross revenues		$ 30,908	$ 33,437	$ 34,439
Net income (loss)		$ (60,901)	$ 15,907	$ 18,342
Net income (loss) (usd per unit)		$ (0.73)	$ 0.19	$ 0.22
Restatement Adjustment [Member]
Condensed Income Statements, Captions [Line Items]
Total gross revenues		$ (350)	$ 7,335	$ (339)
Net income (loss)		(350)	7,335	(339)
Net income (loss) attributable to common shareholders		$ (322)	$ 7,045	$ (326)
Net income attributable to common shareholders - basic (in dollars per share)		$ (0.01)	$ 0.03	$ 0.00
Net income (loss) attributable to common shareholders - diluted (in dollars per share)		$ (0.01)	$ 0.03	$ (0.01)
Restatement Adjustment [Member] | LCIF [Member]
Condensed Income Statements, Captions [Line Items]
Total gross revenues		$ (350)	$ 7,335	$ (339)
Net income (loss)		$ (678)	$ 6,847	$ (315)
Net income (loss) (usd per unit)		$ (0.01)	$ 0.08	$ 0.00