Stock Compensation Plans and Other Employee Benefit Plans (Summary of Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Stock Options Outstanding [Roll Forward]
Outstanding at beginning of the period (in shares)	1,551,734	1,618,426	1,524,672
Granted (in shares)	562,166	502,517	447,153
Options outstanding in acquired plans (in shares)		16,364
Exercised (in shares)	(313,900)	(273,411)	(176,009)
Forfeited or canceled (in shares)	(101,088)	(312,162)	(177,390)
Outstanding at end of the period (in shares)	1,698,912	1,551,734	1,618,426
Exercisable (in shares)	703,892	720,580	941,741
Vested or expected to vest (in shares)	1,666,096
Stock Options, Weighted Average Strike Price [Roll Forward]
Outstanding at beginning of the period (in dollars per share)	$ 41.32	$ 43.00	$ 42.00
Granted (in dollars per share)	41.04	44.36	46.38
Options outstanding in acquired plans (in dollars per share)		21.18
Exercised (in dollars per share)	37.71	42.82	33.32
Forfeited or canceled (in dollars per share)	48.00	52.53	52.55
Outstanding at end of the period (in dollars per share)	41.50	41.32	43.00
Exercisable (in dollars per share)	39.62	$ 37.64	$ 43.35
Vested or expected to vest (in dollars per share)	$ 41.47
Stock Options Additional Disclosures
Outstanding, Remaining Contractual Term	4 years 7 months 6 days	4 years 4 months 24 days	3 years 6 months
Outstanding, Intrinsic Value	$ 52,790	$ 11,433	$ 9,303
Exercisable, Remaining Contractual Term	3 years 4 months 24 days	3 years 1 month 6 days	2 years
Exercisable, Intrinsic Value	$ 23,195	$ 8,045	$ 6,392
Vested or expected to vest, Remaining Contractual Term	4 years 7 months 6 days
Vested or expected to vest, Intrinsic Value	$ 51,831