Summary of Significant Accounting Policies and Recent Accounting Pronouncements (Narrative) (Details)	12 Months Ended
	Dec. 31, 2017 USD ($) Segment	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Jan. 01, 2017 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of operating segments | Segment	4
Gains (losses) resulting from foreign exchange transactions	$ 1,400,000	$ 1,700,000	$ 100,000
Gain (loss) due to ineffectiveness	0	0	0
Interest differentials paid	100,000	200,000	500,000
Contingent acquisition liability adjustments, net	2,213,000	1,330,000	(13,047,000)
Cumulative-effect adjustment resulting from the adoption of ASU 2016-09		294,000
Deferred tax liabilities	61,131,000	77,737,000
Net debt issuance cost	1,600,000
Restatement Adjustment [Member] | Accounting Standards Update 2016-09 [Member]
Summary Of Significant Accounting Policies [Line Items]
Deferred tax liabilities				$ (300,000)
Retained Earnings [Member]
Summary Of Significant Accounting Policies [Line Items]
Cumulative-effect adjustment resulting from the adoption of ASU 2016-09		(425,000)
Software [Member]
Summary Of Significant Accounting Policies [Line Items]
Capitalized compensation for software development	1,600,000	1,400,000	1,500,000
Client-Facing Software [Member]
Summary Of Significant Accounting Policies [Line Items]
Capitalized compensation for software development	$ 100,000	$ 100,000	$ 0
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Cash equivalents maturity period	90 days
Property, plant and equipment, estimated useful life	7 years
Lease expiration	Dec. 31, 2028
Incentive recovery agreement, service term	5 years
Unsecured employee loan, term	5 years
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful life	3 years
Incentive recovery agreement, service term	1 year
Unsecured employee loan, term	3 years