UNAUDITED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Excluding Life Funds Withheld Assets	Life Funds Withheld Assets	Common Shares	Additional Paid in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) Excluding Life Funds Withheld Assets	Accumulated Other Comprehensive Income (Loss) Life Funds Withheld Assets	Retained Earnings (Deficit)	Non-controlling Interest in Equity of Consolidated Subsidiaries
Balance, beginning of year at Dec. 31, 2015				$ 2,947	$ 8,910,167	$ 686,616			$ 2,077,349	$ 1,977,384
Issuance of common shares				16	15
Buybacks of common shares				(196)	(591,757)				(92,433)
Exercise of stock options				1
Exercise of stock options					1,725
Share-based compensation					21,732				(3,572)
Change in net unrealized gains (losses) on investments, net of tax		$ 555,532	$ 129,238				$ 555,532	$ 129,238
Change in adjustments related to future policy benefit reserves, net of tax	$ 25,762					25,762
Change in net unrealized gains (losses) on affiliate and other investments, net of tax	(38,548)					(38,548)
Change in OTTI losses recognized in other comprehensive income, net of tax	4,119					4,119
Change in underfunded pension liability, net of tax	(949)					(949)
Change in value of cash flow hedge	(87)					(87)
Foreign currency translation adjustments, net of tax	46,904					46,904
Net income (loss) attributable to common shareholders	65,667								65,667
Dividends on common shares									(115,060)
Non-controlling interests - contributions										1,129
Non-controlling interests - distributions										(5,180)
Non-controlling interests										5,436
Non-controlling interest share in change in accumulated other comprehensive income (loss)										(25)
Balance, end of year at Jun. 30, 2016	13,663,932			2,768	8,341,882	1,408,587			1,931,951	1,978,744
Balance, beginning of year at Dec. 31, 2016	12,960,679			2,669	8,068,503	715,546			2,151,794	2,022,167
Issuance of common shares				11	17
Buybacks of common shares	(450,600)			(111)	(333,747)				(116,772)
Exercise of stock options				17
Exercise of stock options					42,614
Share-based compensation					13,526				(6,089)
Change in net unrealized gains (losses) on investments, net of tax		$ 178,477	$ (32,064)				$ 178,477	$ (32,064)
Change in adjustments related to future policy benefit reserves, net of tax	8,569					8,569
Change in net unrealized gains (losses) on affiliate and other investments, net of tax	7,881					7,881
Change in OTTI losses recognized in other comprehensive income, net of tax	2,939					2,939
Change in underfunded pension liability, net of tax	(933)					(933)
Change in value of cash flow hedge	(96)					(96)
Foreign currency translation adjustments, net of tax	40,846					40,846
Net income (loss) attributable to common shareholders	454,463								454,463
Dividends on common shares									(117,508)
Non-controlling interests - contributions										25
Non-controlling interests - distributions										(6,093)
Non-controlling interests										5,459
Non-controlling interest share in change in accumulated other comprehensive income (loss)										297
Balance, end of year at Jun. 30, 2017	$ 13,102,407			$ 2,586	$ 7,790,913	$ 921,165			$ 2,365,888	$ 2,021,855