Earnings Per Share Summary of Computation of Basic and Diluted Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
Net Income (Loss) Available to Common Stockholders, Basic									$ 102,700	$ 110,387	$ 84,242
Weighted Average Number of Shares Outstanding, Basic	16,342,485,000	16,382,798,000	16,560,545,000	15,651,541,000	15,695,522,000	15,686,542,000	15,285,532,000	15,288,332,000	16,234,342	15,488,982	15,295,573
Weighted Average Number Diluted Shares Outstanding Adjustment									95,114	122,507	94,779
Weighted Average Number of Shares Outstanding, Diluted	16,454,553,000	16,475,741,000	16,642,571,000	15,744,777,000	15,764,548,000	15,832,734,000	15,417,607,000	15,431,625,000	16,329,456	15,611,489	15,390,352
Basic (in dollars per share)	$ 1.46	$ 1.90	$ 1.34	$ 1.63	$ 1.67	$ 1.58	$ 1.85	$ 2.04	$ 6.33	$ 7.13	$ 5.51
Diluted (in dollars per share)	$ 1.45	$ 1.89	$ 1.33	$ 1.62	$ 1.67	$ 1.56	$ 1.83	$ 2.02	$ 6.29	$ 7.07	$ 5.47