Consolidated Statement of Stockholders' Deficiency - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance (in shares)	123,792,329	114,501,014	97,482,998
Beginning Balance	$ (122,161)	$ (20,680)	$ (50,605)
Net income	77,266	66,472	49,114
Change in net loss and prior service cost, net of income taxes	(770)	(2,610)	(2,160)
Forward contract adjustments, net of income taxes	17	36	37
Unrealized gain (loss) on long-term investment securities accounted for under the equity method, net of income taxes		1,658	(1,046)
Change in net unrealized gain (loss) on investment securities, net of income taxes	(3,629)	(7,060)	1,229
Net unrealized loss reclassified into net income, net of income taxes	1,450	1,006	6
Unrealized gain (loss) on investment securities, net of income taxes	(2,179)	(6,054)	1,235
Other comprehensive loss, net of tax	(2,932)	(6,970)	(1,934)
Comprehensive income	74,334	59,502	47,180
Distributions and dividends on common stock	(201,107)	(189,838)	(166,898)
Restricted stock grant	0	120	100
Surrender of shares in connection with restricted stock vesting	(4,052)	(2,083)
Effect of stock dividend	0	0	0
Cancellation of shares under share lending agreement	$ 0
Note conversion		$ 25,522	132,021
Beneficial conversion feature of notes payable, net of income taxes			$ 14,648
Exercise of stock options (in shares)	33,501	121,308	464,877
Exercise of stock options	$ 398	$ 1,321	$ 5,051
Cancellation of treasury shares		0
Tax benefit of options exercised	579	821	1,178
Stock-based compensation	10,034	5,621	3,251
Non-controlling interest	248	813	2,733
Distributions to non-controlling interest	$ (11,545)	$ (3,280)	$ (9,339)
Beginning Balance (in shares)	127,739,481.000	123,792,329	114,501,014
Ending Balance	$ (253,272)	$ (122,161)	$ (20,680)
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	$ 12,379	$ 11,450	$ 9,748
Restricted stock grant (in shares)	50,000	1,200,000	1,000,000
Restricted stock grant	$ 5	$ 120	$ 100
Surrender of shares in connection with restricted stock vesting (in shares)	(187,577)	(83,411)
Surrender of shares in connection with restricted stock vesting	$ (18)	$ (8)
Effect of stock dividend (in shares)	6,087,035	5,837,144	5,195,856
Effect of stock dividend	$ 609	$ 584	$ 520
Cancellation of shares under share lending agreement (in shares)	(2,034,212)
Cancellation of shares under share lending agreement	$ (204)
Note conversion (in shares)		2,227,552	10,417,384
Note conversion		$ 223	$ 1,041
Exercise of stock options (in shares)	31,906	110,030	404,776
Exercise of stock options	$ 3	$ 10	$ 41
Ending Balance	12,774	12,379	11,450
Additional Paid-in Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	0	0	0
Distributions and dividends on common stock	(7,173)	(18,120)	(155,067)
Restricted stock grant	(5)		0
Surrender of shares in connection with restricted stock vesting	(4,034)	(2,075)
Cancellation of shares under share lending agreement	204
Note conversion		25,299	130,980
Beneficial conversion feature of notes payable, net of income taxes			14,648
Exercise of stock options	395	1,311	5,010
Cancellation of treasury shares		(12,857)
Tax benefit of options exercised	579	821	1,178
Stock-based compensation	10,034	5,621	3,251
Ending Balance	0	0	0
Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	(210,113)	(97,009)	(121,514)
Net income	71,127	59,198	36,856
Distributions and dividends on common stock	(193,934)	(171,718)	(11,831)
Effect of stock dividend	(609)	(584)	(520)
Ending Balance	(333,529)	(210,113)	(97,009)
Accumulated Other Comprehensive Income
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	(8,313)	(1,343)	591
Change in net loss and prior service cost, net of income taxes	(770)	(2,610)	(2,160)
Forward contract adjustments, net of income taxes	17	36	37
Unrealized gain (loss) on long-term investment securities accounted for under the equity method, net of income taxes		1,658	(1,046)
Change in net unrealized gain (loss) on investment securities, net of income taxes	(3,629)	(7,060)	1,229
Net unrealized loss reclassified into net income, net of income taxes	1,450	1,006	6
Ending Balance	(11,245)	(8,313)	(1,343)
Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	0	(12,857)	(12,857)
Cancellation of treasury shares		12,857
Ending Balance	0	0	(12,857)
Non-controlling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	83,886	79,079	73,427
Net income	6,139	7,274	12,258
Non-controlling interest	248	813	2,733
Distributions to non-controlling interest	(11,545)	(3,280)	(9,339)
Ending Balance	$ 78,728	$ 83,886	$ 79,079