Segment Information (Financial Information) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Segment Reporting Information [Line Items]
Operating Revenues	$ 477,464	$ 459,538	$ 921,349	$ 877,246
Depreciation and Amortization	46,701	47,106	93,544	96,325
Operating Income/(Loss)	90,983	14,590	158,054	35,794
Equity in Earnings/(Losses) of Affiliates, Net of Tax	376	314	888	(108)
Net Income/(Loss) From Continuing Operations	59,005	(5,524)	92,811	(3,791)
Capital Expenditures	26,614	30,054	50,390	63,021
Assets	4,157,125		4,157,125		$ 4,152,371
Operating Segments | PIRM
Segment Reporting Information [Line Items]
Operating Revenues	176,586	183,717	349,641	359,525
Depreciation and Amortization	25,050	26,113	50,061	52,912
Operating Income/(Loss)	30,159	23,026	48,477	37,378
Equity in Earnings/(Losses) of Affiliates, Net of Tax	764	482	1,470	(42)
Net Income/(Loss) From Continuing Operations	30,792	19,272	50,024	30,659
Capital Expenditures	15,494	14,290	29,570	29,903
Assets	1,904,923		1,904,923		1,988,915
Operating Segments | UWS
Segment Reporting Information [Line Items]
Operating Revenues	305,140	279,017	580,761	523,535
Depreciation and Amortization	13,283	13,757	26,528	29,532
Operating Income/(Loss)	96,365	19,779	171,979	65,631
Equity in Earnings/(Losses) of Affiliates, Net of Tax	0	(8)	0	(8)
Net Income/(Loss) From Continuing Operations	98,170	20,377	174,603	65,812
Capital Expenditures	2,112	4,861	4,016	10,629
Assets	2,167,497		2,167,497		2,159,403
Corporate
Segment Reporting Information [Line Items]
Operating Revenues	0	0	0	0
Depreciation and Amortization	8,368	7,236	16,955	13,881
Operating Income/(Loss)	(35,541)	(28,215)	(62,402)	(67,215)
Equity in Earnings/(Losses) of Affiliates, Net of Tax	(388)	(160)	(582)	(58)
Net Income/(Loss) From Continuing Operations	(69,957)	(45,173)	(131,816)	(100,262)
Capital Expenditures	9,008	10,903	16,804	22,489
Assets	5,956,259		5,956,259		5,938,106
Eliminations
Segment Reporting Information [Line Items]
Operating Revenues	(4,262)	(3,196)	(9,053)	(5,814)
Depreciation and Amortization	0	0	0	0
Operating Income/(Loss)	0	0	0	0
Equity in Earnings/(Losses) of Affiliates, Net of Tax	0	0	0	0
Net Income/(Loss) From Continuing Operations	0	0	0	0
Capital Expenditures	0	$ 0	0	$ 0
Assets	$ (5,871,554)		$ (5,871,554)		$ (5,934,053)