CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($)	Total	Common Class A [Member]	Common Class B [Member]	Additional Paid In Capital [Member]	Retained Earnings [Member]
Opening Balance SHARES at Dec. 31, 2014		31,862,294	7,197,532
Conversion of Class B common stock to Class A common stock SHARES		0	0
Compensation expense related to granting of restricted stock awards SHARES		738,195	0
Issuance of common stock related to an incentive plan SHARES		0	0
Common stock repurchase SHARES		0	0
Exercise of stock options SHARES		11,750	0
Purchase of vested employee restricted stock units SHARES	(132,000)	(131,688)	0
Ending Balance SHARES at Dec. 31, 2015		32,480,551	7,197,532
Opening Balance VALUE at Dec. 31, 2014	$ 329,021,000	$ 319,000	$ 72,000	$ 608,515,000	$ (279,885,000)
NET INCOME (LOSS)	29,184,000	0	0	29,184,000	29,184,000
Compensation expense related to granting of restricted stock awards VALUE	5,524,000	7,000	0	5,517,000	0
Issuance of common stock related to an incentive plan VALUE	0	0	0	0	0
Common stock repurchase VALUE	0	0	0	0	0
Purchase of vested employee restricted stock units	(1,562,000)	(1,000)	0	(1,561,000)	0
Forfeitures of dividend equivalents VALUE	0	0	0	0	0
Realization of tax benefit for dividend equivalent payments VALUE	0	0	0	0	0
Exercise of stock options VALUE	35,000	0	0	35,000	0
Preferred stock dividend	(752,000)	0	0	(752,000)	0
Ending Balance VALUE at Dec. 31, 2015	$ 361,450,000	$ 325,000	$ 72,000	611,754,000	(250,701,000)
Conversion of Class B common stock to Class A common stock SHARES		0	0
Compensation expense related to granting of restricted stock awards SHARES		1,095,759	0
Issuance of common stock related to an incentive plan SHARES		31,933	0
Common stock repurchase SHARES		0	0
Exercise of stock options SHARES		134,238	0
Purchase of vested employee restricted stock units SHARES	(232,000)	(232,297)	0
Ending Balance SHARES at Dec. 31, 2016		33,510,184	7,197,532
NET INCOME (LOSS)	$ 38,065,000	$ 0	$ 0	0	38,065,000
Compensation expense related to granting of restricted stock awards VALUE	6,539,000	11,000	0	6,528,000	0
Issuance of common stock related to an incentive plan VALUE	379,000	0	0	379,000	0
Common stock repurchase VALUE	0	0	0	0	0
Purchase of vested employee restricted stock units	(2,268,000)	(2,000)	0	(2,266,000)	0
Payments of dividends VALUE	(8,666,000)	0	0	(8,666,000)	0
Exercise of stock options VALUE	265,000	1,000	0	264,000	0
Preferred stock dividend	(1,788,000)	0	0	(1,788,000)	0
Dividend equivalents, net of forfeitures	(602,000)	0	0	(602,000)	0
Ending Balance VALUE at Dec. 31, 2016	$ 393,374,000	$ 335,000	$ 72,000	605,603,000	(212,636,000)
Conversion of Class B common stock to Class A common stock SHARES		3,152,333	(3,152,333)
Compensation expense related to granting of stock options SHARES	0	0	0
Compensation expense related to granting of restricted stock awards SHARES		2,066,241	0
Issuance of common stock related to an incentive plan SHARES		14,833	0
Common stock repurchase SHARES		(932,600)	0
Exercise of stock options SHARES	8,250	8,250	0
Purchase of vested employee restricted stock units SHARES	(169,000)	(169,279)	0
Ending Balance SHARES at Dec. 31, 2017		139,675,781	4,045,199
NET INCOME (LOSS)	$ 233,849,000	$ 0	$ 0	0	233,849,000
Conversion of Class B common stock to Class A common stock VALUE		32,000	(32,000)	0	0
Compensation expense related to granting of stock options VALUE		0	0	0	0
Compensation expense related to granting of restricted stock awards VALUE	9,567,000	21,000	0	9,546,000	0
Issuance of common stock related to an incentive plan VALUE	182,000	0	0	182,000	0
Common stock repurchase VALUE	(10,675,000)	(9,000)	0	(10,666,000)	0
Purchase of vested employee restricted stock units	(2,565,000)	(2,000)	0	(2,563,000)	0
Payments of dividends VALUE	(29,296,000)	0	0	(29,296,000)	0
Exercise of stock options VALUE	42,000	0	0	42,000	0
Preferred stock dividend	(2,574,000)	0	0	(2,574,000)	0
Dividend equivalents, net of forfeitures	(1,556,000)	0	0	(1,556,000)	0
Net unrealized gain (loss) on derivatives VALUE	5,112,000	0	0	534,000	4,578,000
Ending Balance VALUE at Dec. 31, 2017	1,764,360,000	$ 1,397,000	$ 40,000	1,737,132,000	25,791,000
Shares Issued Pursuant to Acquisition		101,407,494	0
Stock Issued in Acquisition - VALUE	1,161,116,000	$ 1,014,000	$ 0	$ 1,160,102,000	0
Equity Awards assumed in Merger		618,325		0
Stock options assumed in Merger		0	0
Equity awards assumed in Merger VALUE	6,777,000	$ 6,000	$ 0	$ 6,771,000	0
Stock options assumed in Merger VALUE	$ 1,007,000	$ 0	$ 0	$ 1,007,000	$ 0