Bank Loans	3 Months Ended
Mar. 31, 2014
Bank Loans [Abstract]
Bank Loans	5. Bank loans Subsequent to March 31, 2014, the Company modified and extended the terms of its line of credit (the “Credit Facility”) with Wells Fargo Bank, National Association (“Wells Fargo”). The expiration of the Credit Facility was extended from August 1, 2015 to May 1, 2019. The Credit Facility has a borrowing limit of $250.0 million. The rate of interest charged on borrowings was modified to a rate ranging from the London Interbank Offered Rate (“LIBOR”) plus 0.875% to LIBOR plus 1.70% depending on the Company’s credit ratings. Currently, the Company’s rate under the Credit Facility is LIBOR plus 0.925% (revised from 1.10%). In addition, the Company is required to pay an annual facility fee ranging from 0.125% to 0.30% of the borrowing limit depending on the Company’s credit ratings (currently 0.15%). The Company had no balance outstanding on the Credit Facility at March 31, 2014 and December 31, 2013. The Company had $408,000 and $485,000 of unamortized commitment fees as of March 31, 2014 and December 31, 2013, respectively. The Credit Facility requires the Company to meet certain covenants, with all of which the Company was in compliance as of March 31, 2014. Interest on outstanding borrowings is payable monthly. The Company had a term loan with Wells Fargo (the “Term Loan”). Pursuant to the Term Loan, the Company borrowed $250.0 million for a three year term maturing December 31, 2014. The Term Loan was repaid in full in November, 2013. Interest on the amounts borrowed under the Term Loan accrued based on an applicable rate ranging from LIBOR plus 1.15% to LIBOR plus 2.25% depending on the Company’s credit ratings. During 2013, the Company’s rate under the Term Loan was LIBOR plus 1.20%.

5. Bank loans

Subsequent to March 31, 2014, the Company modified and extended the terms of its line of credit (the “Credit Facility”) with Wells Fargo Bank, National Association (“Wells Fargo”). The expiration of the Credit Facility was extended from August 1, 2015 to May 1, 2019. The Credit Facility has a borrowing limit of $250.0 million. The rate of interest charged on borrowings was modified to a rate ranging from the London Interbank Offered Rate (“LIBOR”) plus 0.875% to LIBOR plus 1.70% depending on the Company’s credit ratings. Currently, the Company’s rate under the Credit Facility is LIBOR plus 0.925% (revised from 1.10%). In addition, the Company is required to pay an annual facility fee ranging from 0.125% to 0.30% of the borrowing limit depending on the Company’s credit ratings (currently 0.15%). The Company had no balance outstanding on the Credit Facility at March 31, 2014 and December 31, 2013. The Company had $408,000 and $485,000 of unamortized commitment fees as of March 31, 2014 and December 31, 2013, respectively. The Credit Facility requires the Company to meet certain covenants, with all of which the Company was in compliance as of March 31, 2014. Interest on outstanding borrowings is payable monthly.

The Company had a term loan with Wells Fargo (the “Term Loan”). Pursuant to the Term Loan, the Company borrowed $250.0 million for a three year term maturing December 31, 2014. The Term Loan was repaid in full in November, 2013. Interest on the amounts borrowed under the Term Loan accrued based on an applicable rate ranging from LIBOR plus 1.15% to LIBOR plus 2.25% depending on the Company’s credit ratings. During 2013, the Company’s rate under the Term Loan was LIBOR plus 1.20%.