Summary of Significant Accounting Policies (Earnings Per Share) (Details) - USD ($)	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
Income (numerator) [Abstract]
Net income	$ 1,854,000	$ 20,425,000	$ 11,350,000	$ 17,930,000	$ 7,119,000	$ 61,277,000	$ 6,141,000	$ 14,140,000	$ 51,559,000	$ 88,677,000	$ 21,673,000
Diluted earnings (loss) per share, Net income (loss) available to common shareholders									$ 51,559,000	$ 88,677,000	$ 21,673,000
Shares (denominator) [Abstract]
Basic earnings per share (in shares)									56,765,635	56,343,845	55,686,507
Effect of dilutive securities, Common stock options and restricted stock units (in shares)									573,350	724,461	489,762
Diluted earnings (loss) per share, Net income (loss) available to common shareholders (in shares)									57,338,985	57,068,306	56,176,269
Per share amount [Abstract]
Basic earnings per share (in dollars per share)	$ 0.03	$ 0.36	$ 0.20	$ 0.32	$ 0.13	$ 1.09	$ 0.11	$ 0.25	$ 0.91	$ 1.57	$ 0.39
Effect of dilutive securities, Common stock options and restricted stock units (in dollars per share)									(0.01)	(0.02)
Net income per share - diluted	$ 0.03	$ 0.36	$ 0.20	$ 0.32	$ 0.13	$ 1.07	$ 0.11	$ 0.25	$ 0.90	$ 1.55	$ 0.39
Continuing Operations [Member]
Income (numerator) [Abstract]
Net income									$ 51,268,000	$ 87,540,000	$ 17,338,000
Diluted earnings (loss) per share, Net income (loss) available to common shareholders									$ 51,268,000	$ 87,540,000	$ 17,338,000
Shares (denominator) [Abstract]
Basic earnings per share (in shares)									56,765,635	56,343,845	55,686,507
Effect of dilutive securities, Common stock options and restricted stock units (in shares)									573,350	724,461	489,762
Diluted earnings (loss) per share, Net income (loss) available to common shareholders (in shares)									57,338,985	57,068,306	56,176,269
Per share amount [Abstract]
Basic earnings per share (in dollars per share)									$ 0.90	$ 1.55	$ 0.31
Effect of dilutive securities, Common stock options and restricted stock units (in dollars per share)									(0.01)	(0.02)
Net income per share - diluted									$ 0.89	$ 1.53	$ 0.31
Discontinued Operations [Member]
Income (numerator) [Abstract]
Net income									$ 291,000	$ 1,137,000	$ 4,335,000
Diluted earnings (loss) per share, Net income (loss) available to common shareholders									$ 291,000	$ 1,137,000	$ 4,335,000
Shares (denominator) [Abstract]
Basic earnings per share (in shares)									56,765,635	56,343,845	55,686,507
Effect of dilutive securities, Common stock options and restricted stock units (in shares)									573,350	724,461	489,762
Diluted earnings (loss) per share, Net income (loss) available to common shareholders (in shares)									57,338,985	57,068,306	56,176,269
Per share amount [Abstract]
Basic earnings per share (in dollars per share)									$ 0.01	$ 0.02	$ 0.08
Net income per share - diluted									$ 0.01	$ 0.02	$ 0.08