Income Taxes (Unrecognized Tax Benefits) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of unrecognized tax benefits
Balance at Beginning of Period	$ 1,640,000	$ 1,571,000	$ 2,076,000
Additions based on tax positions related to the current year	0	1,290,000	0
Additions for tax positions of prior years	0	341,000	0
Additions from current year acquisitions	4,121,000	0	0
Reductions for tax positions of prior years	(1,290,000)	0	0
Reductions as a result of a lapse of applicable statutes of limitations	(10,000)	(1,562,000)	(505,000)
Balance at End of Period	$ 4,461,000	$ 1,640,000	$ 1,571,000