Quarterly Results of Operations (Unaudited) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Summary of Unaudited Quarterly Results of Operations
Revenues	$ 1,241,243,000	$ 1,236,379,000	$ 1,125,912,000	$ 1,096,965,000	$ 1,104,257,000	$ 1,091,483,000	$ 1,058,602,000	$ 1,062,298,000	$ 4,700,499,000	$ 4,316,641,000	$ 4,281,160,000
Net income (loss) attributable to common stockholders	$ 101,763,000	$ 64,384,000	$ 154,432,000	$ 437,671,000	$ (111,523,000)	$ 74,043,000	$ 188,429,000	$ 312,639,000	$ 758,250,000	$ 463,595,000	$ 1,012,397,000
Net income (loss) attributable to common stockholders per share:
Basic (in USD per share)	$ 0.27	$ 0.17	$ 0.42	$ 1.18	$ (0.31)	$ 0.20	$ 0.51	$ 0.86	$ 2.03	$ 1.26	$ 2.83
Diluted (in USD per share)	$ 0.27	$ 0.17	$ 0.41	$ 1.17	$ (0.31)	$ 0.20	$ 0.51	$ 0.86	$ 2.02	$ 1.26	$ 2.81
Quarterly Results of Operations (Textuals) [Abstract]
Impairment of assets					$ 99,821,100				$ 115,579,000	$ 124,483,000	$ 37,207,000
Provision for Loan and Lease Losses					$ 62,966,000				$ 0	$ 62,966,000	$ 10,215,000