Stockholders' Equity (Narrative) (Details)	3 Months Ended
	Jun. 30, 2017 USD ($) vote $ / shares shares	Jun. 30, 2016 $ / shares shares	Mar. 31, 2017 $ / shares shares
Class of Stock [Line Items]
Common stock, shares authorized (in shares) | shares	250,000,000		250,000,000
Common stock, par value (in USD per share) | $ / shares	$ 0.01		$ 0.01
Preferred stock, shares authorized (in shares) | shares	5,000,000		5,000,000
Preferred stock, par value (in USD per share) | $ / shares	$ 0.01		$ 0.01
Voting rights, number of votes per common share owned | vote	1
Dividends declared on common stock | $	$ 0
Restricted Shares
Class of Stock [Line Items]
Restricted stock repurchased during period (in shares) | shares	19,616	24,988
Restricted stock acquired, average cost per share (in USD per share) | $ / shares	$ 52.36	$ 55.82