Accumulated Other Comprehensive Loss (After-tax Components of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands		3 Months Ended			6 Months Ended
		Jun. 30, 2019		Jun. 30, 2018	Jun. 30, 2019		Jun. 30, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	[1]	$ 2,474		$ (3,988)	$ (6,387)		$ (2,700)
Other comprehensive loss before reclassifications	[1]	(8,544)		(1,191)	(11,314)		(2,311)
Amounts reclassified from accumulated other comprehensive income (loss) (b)	[1]	(171)	[2]	(168)	11,460	[2]	(336)
Net current-period other comprehensive income (loss)	[1]	(8,715)		(1,359)	146		(2,647)
Ending balance	[1]	(6,241)		(5,347)	(6,241)		(5,347)
Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	[1]	(3,748)		0	(126)		0
Other comprehensive loss before reclassifications	[1]	(5,952)		51	(9,710)		51
Amounts reclassified from accumulated other comprehensive income (loss) (b)	[1]	0	[2]	0	136	[2]	0
Net current-period other comprehensive income (loss)	[1]	(5,952)		51	(9,574)		51
Ending balance	[1]	(9,700)		51	(9,700)		51
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	[1]	1,059		(8,866)	(11,550)		(7,716)
Other comprehensive loss before reclassifications	[1]	(2,035)		(1,123)	(1,092)		(2,273)
Amounts reclassified from accumulated other comprehensive income (loss) (b)	[1]	0	[2]	0	11,666	[2]	0
Net current-period other comprehensive income (loss)	[1]	(2,035)		(1,123)	10,574		(2,273)
Ending balance	[1]	(976)		(9,989)	(976)		(9,989)
Investment in Convertible Preferred Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	[1]	258		257	258		344
Other comprehensive loss before reclassifications	[1]	0		0	0		(87)
Amounts reclassified from accumulated other comprehensive income (loss) (b)	[1]	0	[2]	0	0	[2]	0
Net current-period other comprehensive income (loss)	[1]	0		0	0		(87)
Ending balance	[1]	258		257	258		257
Defined Benefit Plan Items
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	[1]	4,905		4,621	5,031		4,672
Other comprehensive loss before reclassifications	[1]	(557)		(119)	(512)		(2)
Amounts reclassified from accumulated other comprehensive income (loss) (b)	[1]	(171)	[2]	(168)	(342)	[2]	(336)
Net current-period other comprehensive income (loss)	[1]	(728)		(287)	(854)		(338)
Ending balance	[1]	$ 4,177		$ 4,334	$ 4,177		$ 4,334

[1] All amounts are net of tax. Amounts in parentheses indicate debits

[2] Reflects foreign currency translation adjustments attributable to the consolidation of Thompsons Limited as summarized in Note 17.