Acquisitions (Assets Acquired and Liabilities Assumed) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill	$ 47,422	$ 45,146	$ 33,630
Ultriva, Inc. [Member]
Business Acquisition [Line Items]
Cash	383
Accounts receivable	737
Other current assets	41
Canadian tax credit receivable	0
Property and equipment	16
Goodwill	4,700
Other assets	32
Total assets acquired	8,829
Accounts payable	(197)
Accrued expense and other	(284)
Deferred tax liabilities	0
Deferred revenue	(760)
Canadian tax credit liability to seller	0
Total liabilities assumed	(1,241)
Total consideration	7,588
Ultriva, Inc. [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets	1,820
Ultriva, Inc. [Member] | Trade Names [Member]
Business Acquisition [Line Items]
Intangible assets	140
Ultriva, Inc. [Member] | Technology [Member]
Business Acquisition [Line Items]
Intangible assets	$ 960
Solution Q [Member]
Business Acquisition [Line Items]
Cash		352
Accounts receivable		893
Other current assets		24
Canadian tax credit receivable		71
Property and equipment		28
Goodwill		5,206
Other assets		14
Total assets acquired		9,458
Accounts payable		(52)
Accrued expense and other		(223)
Deferred tax liabilities		(428)
Deferred revenue		(2,242)
Canadian tax credit liability to seller		(39)
Total liabilities assumed		(2,984)
Total consideration		6,474
Solution Q [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets		2,230
Solution Q [Member] | Trade Names [Member]
Business Acquisition [Line Items]
Intangible assets		100
Solution Q [Member] | Technology [Member]
Business Acquisition [Line Items]
Intangible assets		540
Mobile Commons [Member]
Business Acquisition [Line Items]
Cash		286
Accounts receivable		1,242
Other current assets		147
Canadian tax credit receivable		0
Property and equipment		54
Goodwill		7,244
Other assets		47
Total assets acquired		11,920
Accounts payable		(313)
Accrued expense and other		(463)
Deferred tax liabilities		0
Deferred revenue		(144)
Canadian tax credit liability to seller		0
Total liabilities assumed		(920)
Total consideration		11,000
Mobile Commons [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets		1,620
Mobile Commons [Member] | Trade Names [Member]
Business Acquisition [Line Items]
Intangible assets		130
Mobile Commons [Member] | Technology [Member]
Business Acquisition [Line Items]
Intangible assets		$ 1,150
FileBound [Member]
Business Acquisition [Line Items]
Cash			182
Accounts receivable			1,940
Other current assets			153
Canadian tax credit receivable			0
Property and equipment			927
Goodwill			7,188
Other assets			21
Total assets acquired			16,371
Accounts payable			(113)
Accrued expense and other			(266)
Deferred tax liabilities			0
Deferred revenue			(1,342)
Canadian tax credit liability to seller			0
Total liabilities assumed			(1,721)
Total consideration			14,650
FileBound [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets			3,600
FileBound [Member] | Trade Names [Member]
Business Acquisition [Line Items]
Intangible assets			320
FileBound [Member] | Technology [Member]
Business Acquisition [Line Items]
Intangible assets			2,040
ComSci [Member]
Business Acquisition [Line Items]
Cash			104
Accounts receivable			951
Other current assets			47
Canadian tax credit receivable			0
Property and equipment			61
Goodwill			3,851
Other assets			8
Total assets acquired			8,012
Accounts payable			(260)
Accrued expense and other			(106)
Deferred tax liabilities			0
Deferred revenue			(78)
Canadian tax credit liability to seller			0
Total liabilities assumed			(444)
Total consideration			7,568
ComSci [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets			2,000
ComSci [Member] | Trade Names [Member]
Business Acquisition [Line Items]
Intangible assets			180
ComSci [Member] | Technology [Member]
Business Acquisition [Line Items]
Intangible assets			810
Clickability [Member]
Business Acquisition [Line Items]
Cash			0
Accounts receivable			1,773
Other current assets			297
Canadian tax credit receivable			0
Property and equipment			1,519
Goodwill			3,401
Other assets			0
Total assets acquired			14,140
Accounts payable			(154)
Accrued expense and other			(100)
Deferred tax liabilities			0
Deferred revenue			(1,605)
Canadian tax credit liability to seller			0
Total liabilities assumed			(1,859)
Total consideration			12,281
Clickability [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets			4,400
Clickability [Member] | Trade Names [Member]
Business Acquisition [Line Items]
Intangible assets			250
Clickability [Member] | Technology [Member]
Business Acquisition [Line Items]
Intangible assets			$ 2,500