Combined Consolidated Statements of Changes in Equity (Unaudited) - USD ($) $ in Thousands	Total	Additional Paid-in-Capital	Treasury Stock	Retained Earnings/(Dividends in Excess of Earnings)	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests Operating Partnership	Noncontrolling Interests Consolidated Joint Ventures	Class A Common Stock	Class A Common Stock Common Stock	Class B Common Stock	Class B Common Stock Common Stock
Beginning Balance at Dec. 31, 2014	$ 1,505,207	$ 725,538	$ 0	$ 44,187	$ 15,656	$ 711,674	$ 8,101		$ 51		$ 0
Beginning Balance (in shares) at Dec. 31, 2014									51,432,000		47,647,000
Increase Decrease in Stockholders' Equity
Contributions	74						74
Distributions	(72,603)					(68,673)	(3,930)
Amendment of the par value of the Class B shares from no par value per share to $0.001 per share	0					(47)					$ 47
Equity based compensation	13,788	417				13,371
Grants of restricted stock	0	(1)							$ 1
Grants of restricted stock (in shares)									700,000
Purchase of treasury stock	(994)		(994)
Purchase of treasury stock (in shares)									(84,000)
Re-issuance of treasury stock	0
Re-issuance of treasury stock (in shares)									26,000
Shares acquired to satisfy minimum required federal and state tax withholding on vesting restricted stock and units	(4,897)		(4,818)			(79)
Shares acquired to satisfy minimum required federal and state tax withholding on vesting restricted stock and units (in shares)									(262,000)		(5,000)
Forfeitures	0
Forfeitures (in shares)									(188,000)
Dividends declared	(57,390)			(57,390)
Exchange of noncontrolling interest for common stock	0	53,011			645	(53,656)			$ 3		$ (3)
Exchange of noncontrolling interest for common stock (in shares)									3,586,000		(3,586,000)
Adjustment to the Tax Receivable Agreement as a result of the exchange of Class B shares	(1,366)	(1,366)
Net income (loss)	146,134			73,821		70,745	1,568
Other comprehensive income	(36,545)				(20,046)	(16,499)
Rebalancing of ownership percentage between Company and Operating Partnership	0	(733)			189	544
Ending Balance at Dec. 31, 2015	1,491,408	776,866	(5,812)	60,618	(3,556)	657,380	5,813		$ 55		$ 44
Ending Balance (in shares) at Dec. 31, 2015									55,210,000		44,056,000
Increase Decrease in Stockholders' Equity
Contributions	250					250	0
Distributions	(39,349)					(39,040)	(309)
Equity based compensation	12,694	383				12,311
Grants of restricted stock	0	(1)							$ 1
Grants of restricted stock (in shares)									794,000
Purchase of treasury stock	(4,652)		(4,652)
Purchase of treasury stock (in shares)									(424,000)
Shares acquired to satisfy minimum required federal and state tax withholding on vesting restricted stock and units	(786)		(780)			(6)
Shares acquired to satisfy minimum required federal and state tax withholding on vesting restricted stock and units (in shares)									(73,000)		(1,000)
Forfeitures	0
Forfeitures (in shares)									(48,000)
Dividends declared	(52,829)			(52,829)
Stock dividends	0	64,090		(64,100)					$ 6		$ 4
Stock dividends (in shares)									5,606,000		4,469,000
Exchange of noncontrolling interest for common stock	(1,412)	54,116			928	(56,456)			$ 4		$ (4)
Exchange of noncontrolling interest for common stock (in shares)								4,135,309	4,135,000	(4,135,309)	(4,135,000)
Net income (loss)	42,099			24,871		17,664	(436)
Other comprehensive income	53,275				30,171	23,104
Rebalancing of ownership percentage between Company and Operating Partnership	0	5,207			350	(5,557)
Ending Balance at Sep. 30, 2016	$ 1,500,698	$ 900,661	$ (11,244)	$ (31,440)	$ 27,893	$ 609,650	$ 5,068		$ 66		$ 44
Ending Balance (in shares) at Sep. 30, 2016									65,200,000		44,389,000