Employee Benefit Plans (Schedule of RSU Activity) (Details) - RSUs shares in Thousands	6 Months Ended
	Jun. 30, 2019 $ / shares shares
Number of shares
Beginning balance (in shares) | shares	1,627
Granted (in shares) | shares	489
Vested (in shares) | shares	(502)
Cancelled (in shares) | shares	(53)
Ending balance (in shares) | shares	1,561
Weighted Average Grant Date Fair Value Per Share
Beginning Balance (in dollars per share) | $ / shares	$ 34.31
Granted (in dollars per share) | $ / shares	33.36
Vested (in dollars per share) | $ / shares	31.29
Cancelled (in dollars per share) | $ / shares	35.59
Ending Balance (in dollars per share) | $ / shares	$ 34.94